Decoding Honda Engine Codes OBD2: A Comprehensive Guide

Navigating the complexities of your vehicle’s health can be daunting, especially when that mysterious check engine light illuminates on your Honda’s dashboard. Fortunately, the On-Board Diagnostics II (OBD2) system is designed to help pinpoint potential issues. This guide serves as your comprehensive resource to understanding Honda Engine Codes Obd2, empowering you to diagnose problems effectively and maintain your vehicle’s optimal performance.

Understanding OBD2 codes is crucial for every Honda owner. These codes, generated by your car’s computer, are your first clue when something isn’t functioning correctly within your engine or related systems. While a check engine light can be alarming, it’s your car’s way of communicating – telling you there’s a problem that needs attention. Ignoring it can lead to more significant damage and costly repairs down the road.

This article will delve into a detailed list of Honda OBD2 engine codes, providing insights into what each code signifies. We’ll break down common codes, explain potential causes, and offer guidance on how to approach diagnosis. Whether you’re a seasoned DIY mechanic or a Honda owner simply wanting to be informed, this guide will equip you with the knowledge to understand and address Honda engine codes OBD2.

Common Honda OBD2 Engine Codes Explained

Honda OBD2 engine codes are standardized alphanumeric codes that provide specific information about potential malfunctions within your vehicle. They are read using an OBD2 scanner, a tool readily available to both professionals and car owners. The codes typically follow a format, starting with a letter indicating the system (P for Powertrain, B for Body, C for Chassis, U for Network), followed by four numerical digits that specify the fault area and the specific problem.

Below is an extensive list of Honda OBD2 engine codes, categorized for easier navigation and understanding. This list, derived from Honda service information, covers a wide range of potential issues your Honda might encounter.

Fuel and Air Metering Codes

These codes relate to issues with the fuel and air mixture in your engine, crucial for efficient combustion and performance.

P0010 – Variable Valve Timing Control (VTC) Oil Control Solenoid Valve Malfunction: Indicates a problem with the VTC solenoid valve, which controls oil flow to the VTC actuator, affecting valve timing.
P0011 – Variable Valve Timing Control (VTC) System Malfunction: Signals a broader issue within the VTC system, potentially impacting engine performance and fuel efficiency.
P0101 – Mass Airflow (MAF) Sensor Range/Performance Problem: Suggests the MAF sensor, which measures the air entering the engine, is providing inaccurate readings or is malfunctioning.
P0102 – Mass Airflow (MAF) Sensor Circuit Low Voltage: Points to a low voltage issue in the MAF sensor circuit, possibly due to wiring problems or a faulty sensor.
P0103 – Mass Airflow (MAF) Sensor Circuit High Voltage: Indicates a high voltage issue in the MAF sensor circuit, similar to P0102, potentially stemming from wiring or sensor faults.
P0106 – Manifold Absolute Pressure (MAP) Sensor Range/Performance Problem: Signifies that the MAP sensor, which measures manifold pressure, is providing incorrect data or is not performing as expected.
P0107 – Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage: Indicates a low voltage problem in the MAP sensor circuit, potentially caused by wiring issues or a faulty sensor.
P0108 – Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage: Suggests a high voltage problem in the MAP sensor circuit, similar to P0107, possibly due to wiring or sensor malfunctions.
P0111 – Intake Air Temperature (IAT) Sensor Circuit Range/Performance Problem: Indicates the IAT sensor, which measures the temperature of the incoming air, is providing inaccurate readings or is malfunctioning.
P0112 – Intake Air Temperature (IAT) Sensor Circuit Low Voltage: Points to a low voltage issue in the IAT sensor circuit, possibly due to wiring problems or a faulty sensor.
P0113 – Intake Air Temperature (IAT) Sensor Circuit High Voltage: Indicates a high voltage issue in the IAT sensor circuit, similar to P0112, potentially stemming from wiring or sensor faults.

Engine Temperature and Cooling System Codes

These codes highlight problems within the engine’s temperature regulation system, crucial for preventing overheating and engine damage.

P0116 – Engine Coolant Temperature (ECT) Sensor Circuit Range/Performance Problem: Suggests the ECT sensor, which monitors engine coolant temperature, is providing inaccurate readings or is malfunctioning.
P0117 – Engine Coolant Temperature (ECT) Sensor Circuit Low Input: Points to a low input issue in the ECT sensor circuit, possibly due to wiring problems or a faulty sensor.
P0118 – Engine Coolant Temperature (ECT) Sensor Circuit High Input: Indicates a high input issue in the ECT sensor circuit, similar to P0117, potentially stemming from wiring or sensor faults.
P0125 – Engine Coolant Temperature (ECT) Sensor Slow Response: Signals that the ECT sensor is responding too slowly to temperature changes, which can affect fuel delivery and engine performance.
P0128 – Cooling System Malfunction: Indicates a general problem within the cooling system, which could be due to issues with the thermostat, radiator, coolant leaks, or other components.

Throttle Position Sensor Codes

These codes relate to the throttle position sensor, which monitors the position of the throttle plate and is essential for controlling engine speed and power.

P0122 – Throttle Position (TP) Sensor Circuit Low Input: Points to a low input issue in the TP sensor circuit, possibly due to wiring problems or a faulty sensor.
P0123 – Throttle Position (TP) Sensor Circuit High Input: Indicates a high input issue in the TP sensor circuit, similar to P0122, potentially stemming from wiring or sensor faults.

Oxygen Sensor and Air/Fuel Ratio Sensor Codes

These codes pertain to the oxygen sensors and air/fuel ratio sensors, which monitor the exhaust gases to ensure the engine is running with the correct air-fuel mixture for optimal emissions and fuel efficiency.

P0131 – Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit Low Voltage: Indicates a low voltage issue in the primary oxygen sensor circuit (Sensor 1, usually located before the catalytic converter).
P0132 – Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Circuit High Voltage: Suggests a high voltage issue in the primary oxygen sensor circuit (Sensor 1).
P0133 – Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) Circuit Slow Response: Signals that the rear air/fuel ratio sensor (Bank 1, Sensor 1) is responding slowly, which can affect fuel trim adjustments.
P0134 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) No Activity Detected: Indicates no signal from the air/fuel ratio sensor (Sensor 1), potentially due to a faulty sensor or wiring issue.
P0135 – Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1) Heater Circuit Malfunction: Points to a problem with the heater circuit of the primary oxygen sensor (Sensor 1), which is needed for the sensor to reach operating temperature quickly.
P0137 – Secondary Heated Oxygen Sensor (Secondary HO2S) Circuit Low Voltage: Indicates a low voltage issue in the secondary oxygen sensor circuit (usually located after the catalytic converter).
P0138 – Secondary Heated Oxygen Sensor (Secondary HO2S) Circuit High Voltage: Suggests a high voltage issue in the secondary oxygen sensor circuit.
P0139 – Secondary Heated Oxygen Sensor (Secondary HO2S) Slow Response: Signals that the secondary oxygen sensor is responding slowly, which can indicate catalytic converter inefficiency.
P0141 – Secondary Heated Oxygen Sensor (Secondary HO2S) (Sensor 2) Heater Circuit Malfunction: Points to a problem with the heater circuit of the secondary oxygen sensor (Sensor 2).
P0143 – Third Heated Oxygen Sensor (Third HO2S) (Sensor 3) Circuit Low Voltage: Indicates a low voltage issue in the third oxygen sensor circuit (Sensor 3, if applicable in your Honda model).
P0144 – Third Heated Oxygen Sensor (Third HO2S) (Sensor 3) Circuit High Voltage: Suggests a high voltage issue in the third oxygen sensor circuit (Sensor 3).
P0145 – Third Heated Oxygen Sensor (Third HO2S) (Sensor 3) Circuit Slow Response: Signals that the third oxygen sensor is responding slowly.
P0147 – Third Heated Oxygen Sensor (Third HO2S) (Sensor 3) Heater Circuit Malfunction: Points to a problem with the heater circuit of the third oxygen sensor (Sensor 3).
P0153 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) Circuit Slow Response: Signals slow response from the front air/fuel ratio sensor in Bank 2, Sensor 1 (for V-engines).
P0154 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) Heater System Malfunction: Indicates a malfunction in the heater system of the front air/fuel ratio sensor in Bank 2, Sensor 1.
P0155 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) Heater Circuit Malfunction: Points to a heater circuit problem for the front air/fuel ratio sensor in Bank 2, Sensor 1.
P0157 – Front Secondary Heated Oxygen Sensor (Secondary HO2S) (Bank 2, Sensor 2) Circuit Low Voltage: Indicates low voltage in the front secondary oxygen sensor circuit in Bank 2, Sensor 2.
P0158 – Front Secondary Heated Oxygen Sensor (Secondary HO2S) (Bank 2, Sensor 2) Circuit High Voltage: Suggests high voltage in the front secondary oxygen sensor circuit in Bank 2, Sensor 2.
P0159 – Front Secondary Heated Oxygen Sensor (Secondary HO2S) (Bank 2, Sensor 2) Circuit Slow Response: Signals slow response from the front secondary oxygen sensor in Bank 2, Sensor 2.
P0161 – Front Secondary Heated Oxygen Sensor (Secondary HO2S) (Bank 2, Sensor 2) Heater Circuit Malfunction: Points to a heater circuit problem for the front secondary oxygen sensor in Bank 2, Sensor 2.

Fuel System Codes

These codes indicate issues related to the fuel system, including fuel mixture, pressure, and sensor malfunctions.

P0171 – Fuel System Too Lean: Indicates that the engine is running lean, meaning there is too much air and not enough fuel in the air-fuel mixture.
P0172 – Fuel System Too Rich: Indicates that the engine is running rich, meaning there is too much fuel and not enough air in the air-fuel mixture.
P0174 – Front Bank (Bank 2) Fuel System Too Lean: Similar to P0171, but specific to Bank 2 in V-engines.
P0175 – Front Bank (Bank 2) Fuel System Too Rich: Similar to P0172, but specific to Bank 2 in V-engines.
P0191 – Fuel Pressure Sensor Range/Performance Problem: Suggests the fuel pressure sensor is providing inaccurate readings or is malfunctioning.
P0192 – Fuel Pressure Sensor Circuit Low Voltage: Points to a low voltage issue in the fuel pressure sensor circuit.
P0193 – Fuel Pressure Sensor Circuit High Voltage: Indicates a high voltage issue in the fuel pressure sensor circuit.

Engine Oil Temperature Sensor Codes

These codes pertain to the engine oil temperature sensor, which monitors the temperature of the engine oil.

P0196 – EOT Sensor/Range Performance Problem: Suggests the engine oil temperature (EOT) sensor is providing inaccurate readings or is malfunctioning.
P0197 – EOT Sensor Circuit Low Voltage: Points to a low voltage issue in the EOT sensor circuit.
P0198 – EOT Sensor Circuit High Voltage: Indicates a high voltage issue in the EOT sensor circuit.

Accelerator/Throttle Position Sensor Codes (Sensor 2)

These codes relate to a secondary throttle position sensor, if equipped in your Honda model.

P0222 – Throttle Position (TP) Sensor 2 Circuit Low Voltage: Points to a low voltage issue in the secondary TP sensor circuit.
P0223 – Throttle Position (TP) Sensor 2 Circuit High Voltage: Indicates a high voltage issue in the secondary TP sensor circuit.

Misfire Codes

Misfire codes indicate that one or more cylinders are not firing correctly, which can lead to rough running, reduced power, and potential engine damage.

P0300 – Random Misfire: Indicates misfires are occurring in multiple cylinders, but the specific cylinder is not identified.
P0301 – No. 1 Cylinder Misfire: Specifies a misfire in cylinder number 1.
P0302 – No. 2 Cylinder Misfire: Specifies a misfire in cylinder number 2.
P0303 – No. 3 Cylinder Misfire: Specifies a misfire in cylinder number 3.
P0304 – No. 4 Cylinder Misfire: Specifies a misfire in cylinder number 4.
P0305 – No. 5 Cylinder Misfire: Specifies a misfire in cylinder number 5 (for engines with 5 or more cylinders).
P0306 – No. 6 Cylinder Misfire: Specifies a misfire in cylinder number 6 (for engines with 6 or more cylinders).

Knock Sensor Code

This code relates to the knock sensor, which detects engine knocking or detonation, protecting the engine from damage.

P0325 – Knock Sensor Circuit Malfunction: Indicates a problem with the knock sensor circuit, potentially preventing the engine from detecting and responding to knock.

Crankshaft and Camshaft Position Sensor Codes

These codes relate to the crankshaft position sensor (CKP) and camshaft position sensor (CMP), which are crucial for engine timing and ignition.

P0335 – Crankshaft Position (CKP) Sensor Circuit No Signal: Indicates no signal from the CKP sensor, which can prevent the engine from starting or running.
P0336 – P0339 Crankshaft Position (CKP) Sensor Circuit Intermittent Interruption: Signals an intermittent signal issue with the CKP sensor.
P0340 – Camshaft Position (CMP) Sensor No Signal: Indicates no signal from the CMP sensor, which can also prevent starting or cause rough running.
P0341 – Camshaft Position (CMP) Sensor A Intermittent Interruption: Signals an intermittent signal issue with CMP sensor A.
P0341 – Variable Valve Timing Control (VTC) Phase Gap: Indicates a phase gap issue with the VTC system, potentially related to timing chain or VTC actuator problems.
P0344 – Camshaft Position (CMP) Sensor Intermittent Interruption: Signals another intermittent signal issue with the CMP sensor.
P0365 – Camshaft Position (CMP) Sensor B No Signal: Indicates no signal from CMP sensor B (for engines with multiple camshafts).
P0366 – P0369 Camshaft Position (CMP) Sensor B Intermittent Interruption: Signals an intermittent signal issue with CMP sensor B.
P0385 – Crankshaft Position (CKP) Sensor B No Signal: Indicates no signal from a secondary CKP sensor B (if equipped).
P0389 – Crankshaft Position (CKP) Sensor B Intermittent Interruption: Signals an intermittent signal issue with CKP sensor B.

Exhaust Gas Recirculation (EGR) and Air Injection System Codes

These codes relate to the emission control systems, specifically the EGR system and secondary air injection system.

P0401 – Exhaust Gas Recirculation (EGR) Insufficient Flow: Indicates insufficient flow through the EGR system, which reduces NOx emissions.
P0404 – Exhaust Gas Recirculation (EGR) Control Circuit Range/Performance Problem: Suggests a problem with the EGR control circuit, affecting EGR system operation.
P0406 – Exhaust Gas Recirculation (EGR) Valve Position Sensor Circuit High Voltage: Points to a high voltage issue in the EGR valve position sensor circuit.
P0410 – Air Pump Circuit Malfunction: Indicates a malfunction in the secondary air injection pump circuit.
P0411 – Secondary Air Injection System Incorrect Flow: Signals incorrect flow in the secondary air injection system, which helps reduce emissions during cold starts.

Catalytic Converter Efficiency Codes

These codes indicate issues with the catalytic converter’s efficiency in reducing harmful emissions.

P0420 – Catalyst System Efficiency Below Threshold: Indicates that the catalytic converter’s efficiency is below the required threshold.
P0430 – Front Bank Catalyst System Efficiency Below Threshold (Bank 2): Similar to P0420, but specific to the catalytic converter in Bank 2 (for V-engines).

Evaporative Emission (EVAP) System Codes

These codes relate to the EVAP system, which prevents fuel vapors from escaping into the atmosphere.

P0441 – Evaporative Emission (EVAP) Control System Incorrect Purge Flow: Indicates incorrect purge flow in the EVAP system.
P0442 – Evaporative Emission (EVAP) System Small Leak Detected: Signals a small leak in the EVAP system.
P0443 – Evaporative Emission (EVAP) Canister Purge Valve Circuit Malfunction: Points to a malfunction in the EVAP canister purge valve circuit.
P0451 – Fuel Tank Pressure (FTP) Sensor Range/Performance Problem: Suggests the fuel tank pressure sensor is providing inaccurate readings or is malfunctioning.
P0452 – Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage: Points to a low voltage issue in the fuel tank pressure sensor circuit.
P0453 – Fuel Tank Pressure (FTP) Sensor Circuit High Voltage: Indicates a high voltage issue in the fuel tank pressure sensor circuit.
P0456 – Evaporative Emission (EVAP) System Very Small Leak Detected: Signals a very small leak in the EVAP system.
P0457 – Evaporative Emission (EVAP) System Leak Detected Fuel Fill Cap Loose/Off: Indicates a leak in the EVAP system, often due to a loose or missing fuel cap.
P0461 – Fuel Gauge Sending Unit Range/Performance Problem: Suggests the fuel gauge sending unit is providing inaccurate readings or is malfunctioning.
P0462 – Fuel Gauge Sending Unit Circuit Low Voltage: Points to a low voltage issue in the fuel gauge sending unit circuit.
P0463 – Fuel Gauge Sending Unit Circuit High Voltage: Indicates a high voltage issue in the fuel gauge sending unit circuit.
P0496 – Evaporative Emission (EVAP) System High Purge Flow: Indicates high purge flow in the EVAP system.
P0497 – Evaporative Emission (EVAP) System Low Purge Flow: Indicates low purge flow in the EVAP system.
P0498 – Evaporative Emission (EVAP) Canister Vent Shut Valve Control Circuit Low Voltage: Points to a low voltage issue in the EVAP canister vent shut valve control circuit.
P0499 – Evaporative Emission (EVAP) Canister Vent Shut Valve Control Circuit High Voltage: Indicates a high voltage issue in the EVAP canister vent shut valve control circuit.

Vehicle Speed Sensor (VSS) and Idle Control System Codes

These codes relate to vehicle speed sensing and the idle control system, which maintains a stable engine idle speed.

P0500 – Vehicle Speed Sensor (VSS) Circuit Malfunction: Indicates a malfunction in the VSS circuit.
P0501 – Vehicle Speed Sensor (VSS) Range/Peformance Problem: Suggests the VSS is providing inaccurate readings or is malfunctioning.
P0505 – Idle Control System Malfunction: Indicates a general malfunction in the idle control system.
P0506 – Idle Control System RPM Lower Than Expected: Signals that the engine idle speed is lower than expected.
P0507 – Idle Control System RPM Higher Than Expected: Signals that the engine idle speed is higher than expected.
P0511 – Idle Air Control (IAC) Valve Circuit Malfunction: Points to a malfunction in the IAC valve circuit, which controls idle airflow.

Engine Oil Pressure (EOP) Sensor Codes

These codes relate to the engine oil pressure sensor, which monitors engine oil pressure.

P0521 – EOP Sensor Range/Performance Problem: Suggests the engine oil pressure (EOP) sensor is providing inaccurate readings or is malfunctioning.
P0522 – EOP Sensor Circuit Low Voltage: Points to a low voltage issue in the EOP sensor circuit.
P0523 – EOP Sensor Circuit High Voltage: Indicates a high voltage issue in the EOP sensor circuit.

Engine Control Module (ECM)/Powertrain Control Module (PCM) Codes

These codes indicate issues within the ECM/PCM, the computer that controls the engine and powertrain.

P0560 – ECM Back-up Circuit Low Voltage: Points to a low voltage issue in the ECM backup circuit.
P0563 – Engine Control Module (ECM)/Powertrain Control Module (PCM) Power Source Circuit Unexpected Voltage: Signals unexpected voltage in the ECM/PCM power source circuit.
P0600 – Multiplex Control System Troubleshooting: Indicates a troubleshooting issue with the multiplex control system, a communication network within the vehicle.
P0603 – ECM/PCM Internal Control Module Keep Alive Memory (KAM) Error: Signals an error in the ECM/PCM’s KAM, which stores learned data.
P0606 – ECM/PCM Processor Malfunction: Indicates a malfunction in the ECM/PCM processor itself.
P0685 – ECM/PCM Power Relay Control Circuit Malfunction: Points to a malfunction in the ECM/PCM power relay control circuit.

Intake Manifold Runner Control (IMRC) Codes

These codes relate to the IMRC system, which optimizes airflow into the engine at different speeds.

P0661 – Intake Manifold Runner Control (IMRC) Valve Position Sensor Circuit Low Voltage: Points to a low voltage issue in the IMRC valve position sensor circuit.
P0662 – Intake Manifold Runner Control (IMRC) Valve Position Sensor Circuit High Voltage: Indicates a high voltage issue in the IMRC valve position sensor circuit.
P1077 – Intake Manifold Runner Control (IMRC) System Malfunction (Low rpm): Signals a malfunction in the IMRC system at low RPM.
P1078 – Intake Mainfold Runner Control (IMRC) System Malfunction (High rpm): Signals a malfunction in the IMRC system at high RPM.

Automatic Transmission Control System Codes (P0700 – P0986 & P1630, P1705 – P1895, P2769, P2770)

A significant portion of the listed codes pertain to the automatic transmission control system. These codes are complex and often require specialized diagnostic tools and expertise. They cover a wide range of issues, including:

Transmission Control System Malfunctions (P0700, P0730, P0780, P1890): General problems within the transmission control system.
Transmission Range Switch Circuit Issues (P0705, P0706, P0812, P1705, P1706, P1709): Problems with the switch that indicates the selected gear.
ATF Temperature Sensor Circuit Problems (P0710, P0711, P0712, P0713): Issues with the automatic transmission fluid temperature sensor.
Speed Sensor Circuit Malfunctions (P0715, P0716, P0717, P0718, P0720, P0721, P0722, P0723, P0725, P1884, P1885, P1886, P1888, P1889): Problems with various speed sensors within the transmission.
Shift Control System Problems (P0730, P0731, P0732, P0733, P0734, P0735, P0780, P1730, P1731, P1732, P1733, P1734, P1890): Issues related to gear shifting and shift solenoids.
Torque Converter Clutch System Problems (P0740, P0741, P0743, P1753, P1751, P1768, P2769, P2770): Issues with the torque converter clutch and its solenoid.
A/T Clutch Pressure Control Solenoid Valve Circuit Problems (P0745, P0746, P0747, P0748, P0775, P0776, P0777, P0778, P0795, P0796, P0797, P0798, P0962, P0963, P0966, P0967, P0970, P0971, P1750, P1751, P1773): Issues with the solenoids that control hydraulic pressure for clutch engagement.
Shift Solenoid Valve Circuit Problems (P0750, P0751, P0752, P0753, P0756, P0757, P0758, P0761, P0762, P0763, P0771, P0773, P0973, P0974, P0976, P0977, P0979, P0980, P0982, P0983, P0985, P0986, P1730, P1731, P1732, P1733, P1734): Issues with the shift solenoids that control gear selection.
Transmission Fluid Pressure Switch Circuit Problems (P0842, P0843, P0845, P0847, P0848, P0872, P0873, P1738, P1739, P1740): Issues with pressure switches that monitor transmission fluid pressure.
CVT Specific Codes (P1655, P1660, P1676, P1678, P1870, P1873, P1879, P1894, P1895): Codes specific to Continuously Variable Transmissions (CVT), relating to control valves, speed sensors, and clutch systems.

Due to the complexity of automatic transmission codes, it is highly recommended to consult a qualified automotive technician for diagnosis and repair if you encounter any of these codes.

Barometric Pressure (BARO) Sensor Codes

These codes relate to the barometric pressure sensor, which measures atmospheric pressure.

P1106 – Barometric Pressure (BARO) Sensor Circuit Range/Performance Problem: Suggests the BARO sensor is providing inaccurate readings or is malfunctioning.
P1107 – Barometric Pressure (BARO) Sensor Circuit Low Voltage: Points to a low voltage issue in the BARO sensor circuit.
P1108 – Barometric Pressure (BARO) Sensor Circuit High Voltage: Indicates a high voltage issue in the BARO sensor circuit.
P2227 – Barometric Pressure (BARO) Sensor Circuit Range/Performance Problem: Another code indicating BARO sensor range/performance issues.
P2228 – Barometric Pressure (BARO) Sensor Circuit Low Voltage: Another code indicating low voltage in the BARO sensor circuit.
P2229 – Barometric Pressure (BARO) Sensor Circuit High Voltage: Another code indicating high voltage in the BARO sensor circuit.

Throttle Position Sensor and Manifold Absolute Pressure Sensor Correlation Codes

These codes indicate inconsistencies or correlation issues between the throttle position sensor and manifold absolute pressure sensor readings.

P1121 – Throttle Position (TP) Sensor Lower Than Expected: Signals that the TP sensor reading is lower than expected based on other sensor data.
P1122 – Throttle Position (TP) Sensor Higher Than Expected: Signals that the TP sensor reading is higher than expected.
P1128 – Manifold Absolute Pressure (MAP) Sensor Circuit Lower Than Expected: Signals that the MAP sensor reading is lower than expected.
P1129 – Manifold Absolute Pressure (MAP) Sensor Circuit Higher Than Expected: Signals that the MAP sensor reading is higher than expected.

Oxygen Sensor and Air/Fuel Ratio Sensor Range/Performance and Circuit Codes (Extended)

These codes are further extensions of the oxygen sensor and air/fuel ratio sensor codes, detailing more specific circuit issues and performance problems.

P1130 – Demand for Changing Both Secondary Heated Oxygen Sensor (Secondary HO2S) (Sensor 2) and Third Heated Oxygen Sensor (Third HO2S) (Sensor 3): Indicates a condition requiring changes in both secondary and third oxygen sensor readings.
P1149 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Another code indicating range/performance issues with the air/fuel ratio sensor (Sensor 1).
P1149 – Air/Fuel Ratio Sensor (Sensor 1) Circuit Lean Range: Specifies a lean range issue with the air/fuel ratio sensor (Sensor 1) circuit.
P1157 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS Line High Voltage: Indicates high voltage on the AFS line of the air/fuel ratio sensor (Sensor 1).
P1157 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Circuit High Voltage: Another code indicating high voltage in the air/fuel ratio sensor (Sensor 1) circuit.
P1157 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Another code indicating range/performance issues with the air/fuel ratio sensor (Sensor 1).
P1158 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS- Terminal Low Voltage: Indicates low voltage on the AFS- terminal of the air/fuel ratio sensor (Sensor 1).
P1159 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS+ Terminal Low Voltage: Indicates low voltage on the AFS+ terminal of the air/fuel ratio sensor (Sensor 1).
P1162 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Slow Response: Another code indicating slow response from the air/fuel ratio sensor (Sensor 1).
P1163 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Slow Response: Another code indicating slow response from the air/fuel ratio sensor (Sensor 1).
P1163 – Air/Fuel Ratio Sensor (Sensor 1) Slow Response: Another code indicating slow response from the air/fuel ratio sensor (Sensor 1).
P1164 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Another code indicating range/performance issues with the air/fuel ratio sensor (Sensor 1).
P1164 – Air/Fuel Ratio (AF) Sensor (Sensor 1) Circuit Range/Performance: Another code indicating circuit range/performance issues with the air/fuel ratio sensor (Sensor 1).
P1165 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Another code indicating range/performance issues with the air/fuel ratio sensor (Sensor 1).
P1165 – Air/Fuel Ratio Sensor (Sensor 1) Circuit Range/Performance: Another code indicating circuit range/performance issues with the air/fuel ratio sensor (Sensor 1).
P1166 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Heater System Electrical Problem: Indicates an electrical problem in the heater system of the air/fuel ratio sensor (Sensor 1).
P1166 – Heated Oxgen Sensor Sensor1 (Primary HO2S) Heater Circuit Malfunction: Another code indicating heater circuit malfunction in the primary oxygen sensor (Sensor 1).
P1167 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Heater System Malfunction: Another code indicating heater system malfunction in the air/fuel ratio sensor (Sensor 1).
P1167 – Heated Oxygen Sensor Sensor1 (Primary LAF HO2S) Heater System Malfunction: Another code indicating heater system malfunction in the primary LAF (Lean Air-Fuel) oxygen sensor (Sensor 1).
P1168 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) LABEL Low Voltage: Indicates low voltage on the LABEL line of the air/fuel ratio sensor (Sensor 1).
P1169 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) LABEL High Voltage: Indicates high voltage on the LABEL line of the air/fuel ratio sensor (Sensor 1).
P2195 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Signal Stuck Lean: Signals that the air/fuel ratio sensor (Sensor 1) signal is stuck in a lean condition.
P2197 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) Signal Stuck Lean: Similar to P2195, but specific to Bank 2, Sensor 1.
P2237 – Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) IP Line High Voltage: Indicates high voltage on the IP line of the rear air/fuel ratio sensor (Bank 1, Sensor 1).
P2238 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS+ Line Low Voltage: Another code indicating low voltage on the AFS+ line of the air/fuel ratio sensor (Sensor 1).
P2238 – Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) IP Line Low Voltage: Indicates low voltage on the IP line of the rear air/fuel ratio sensor (Bank 1, Sensor 1).
P2240 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) IP Line High Voltage: Indicates high voltage on the IP line of the front air/fuel ratio sensor (Bank 2, Sensor 1).
P2241 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) IP Line Low Voltage: Indicates low voltage on the IP line of the front air/fuel ratio sensor (Bank 2, Sensor 1).
P2243 – Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) VCENT Line High Voltage: Indicates high voltage on the VCENT line of the rear air/fuel ratio sensor (Bank 1, Sensor 1).
P2245 – Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) VCENT Line Low Voltage: Indicates low voltage on the VCENT line of the rear air/fuel ratio sensor (Bank 1, Sensor 1).
P2247 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) VCENT Line High Voltage: Indicates high voltage on the VCENT line of the front air/fuel ratio sensor (Bank 2, Sensor 1).
P2249 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) VCENT Line Low Voltage: Indicates low voltage on the VCENT line of the front air/fuel ratio sensor (Bank 2, Sensor 1).
P2251 – Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) VS Line High Voltage: Indicates high voltage on the VS line of the rear air/fuel ratio sensor (Bank 1, Sensor 1).
P2252 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) AFS- Line Low Voltage: Another code indicating low voltage on the AFS- line of the air/fuel ratio sensor (Sensor 1).
P2254 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) VS Line High Voltage: Indicates high voltage on the VS line of the front air/fuel ratio sensor (Bank 2, Sensor 1).
P2255 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) VS Line Low Voltage: Indicates low voltage on the VS line of the front air/fuel ratio sensor (Bank 2, Sensor 1).
P2627 – Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) LABEL Circuit Low Voltage: Indicates low voltage on the LABEL circuit of the rear air/fuel ratio sensor (Bank 1, Sensor 1).
P2628 – Rear Air/Fuel Ratio (A/F) Sensor (Bank 1, Sensor 1) LABEL Circuit High Voltage: Indicates high voltage on the LABEL circuit of the rear air/fuel ratio sensor (Bank 1, Sensor 1).
P2630 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) LABEL Circuit Low Voltage: Indicates low voltage on the LABEL circuit of the front air/fuel ratio sensor (Bank 2, Sensor 1).
P2631 – Front Air/Fuel Ratio (A/F) Sensor (Bank 2, Sensor 1) LABEL Circuit High Voltage: Indicates high voltage on the LABEL circuit of the front air/fuel ratio sensor (Bank 2, Sensor 1).
P2A00 – Air/Fuel Ratio (A/F) Sensor (Sensor 1) Range/Performance Problem: Another code indicating range/performance issues with the air/fuel ratio sensor (Sensor 1).
P2A03 – Front A/F Sensor Circuit (Bank 2, Sensor 1) Circuit Range/Performance Problem: Another code indicating circuit range/performance issues with the front air/fuel ratio sensor (Bank 2, Sensor 1).

VTEC System Codes

These codes relate to Honda’s Variable Valve Timing and Lift Electronic Control (VTEC) system, which enhances engine performance and efficiency.

P1253 – P1259 VTEC System Malfunction: General codes indicating a malfunction within the VTEC system.
P2646 – VTEC Oil Pressure Switch Circuit Low Voltage: Points to a low voltage issue in the VTEC oil pressure switch circuit.
P2647 – VTEC Oil Pressure Switch Circuit High Voltage: Indicates a high voltage issue in the VTEC oil pressure switch circuit.
P2648 – VTEC Solenoid Valve Circuit Low Voltage: Points to a low voltage issue in the VTEC solenoid valve circuit.
P2649 – VTEC Solenoid Valve Circuit High Voltage: Indicates a high voltage issue in the VTEC solenoid valve circuit.

Electric Load Detector (ELD) Codes

These codes relate to the Electric Load Detector (ELD), which monitors the electrical load on the charging system.

P1297 – Electric Load Detector (ELD) Circuit Low Voltage: Points to a low voltage issue in the ELD circuit.
P1298 – Electric Load Detector (ELD) Circuit High Voltage: Indicates a high voltage issue in the ELD circuit.

Random Misfire Code (Extended)

P1300 – Random Misfire: Another code indicating random misfires.

Knock Sensor Power Source Code

P1324 – Knock Sensor Power Source Circuit Low Voltage: Points to a low voltage issue in the knock sensor power source circuit.

Engine Speed (RPM) Fluctuation Sensor Codes

These codes relate to sensors that detect engine speed fluctuations.

P1336 – Engine Speed (RPM) Fluctuation Sensor Intermittent Interruption: Signals an intermittent signal issue with the engine speed fluctuation sensor.
P1337 – Engine Speed (RPM) Fluctuation Sensor No Signal: Indicates no signal from the engine speed fluctuation sensor.

Ignition Coil Power Circuit Code

P1355 – Front Ignition Coil Power Circuit Malfunction: Points to a malfunction in the front ignition coil power circuit.

Crankshaft/Top Dead Center (TDC) Sensor and Camshaft/Top Dead Center (TDC) Sensor Codes

These codes relate to the crankshaft and camshaft position sensors, sometimes also referred to as Top Dead Center (TDC) sensors.

P1359 – Crankshaft Position (CKP)/Top Dead Center (TDC) Sensor Circuit Malfunction: Indicates a malfunction in the CKP/TDC sensor circuit.
P1361 – Camshaft Position (CMP) Sensor A (Top Dead Center (TDC) Sensor) Intermittent Interruption: Signals an intermittent signal issue with CMP/TDC sensor A.
P1361 – Top Dead Center (TDC) Sensor Intermittent Interruption: Another code indicating intermittent signal issue with the TDC sensor.
P1362 – Camshaft Position (CMP) Sensor A (Top Dead Center (TDC) Sensor) No Signal: Indicates no signal from CMP/TDC sensor A.
P1362 – Top Dead Center (TDC) Sensor No Signal: Another code indicating no signal from the TDC sensor.
P1366 – Camshaft Position (CMP) Sensor B (Top Dead Center (TDC) Sensor) Intermittent Interruption: Signals an intermittent signal issue with CMP/TDC sensor B.
P1366 – Top Dead Center (TDC) Sensor 2 Intermittent Interruption: Another code indicating intermittent signal issue with TDC sensor 2.
P1367 – Camshaft Position (CMP) Sensor B (Top Dead Center (TDC) Sensor) No Signal: Indicates no signal from CMP/TDC sensor B.
P1367 – Top Dear Center (TDC) Sensor 2 No Signal: Another code indicating no signal from TDC sensor 2.

Cylinder Position (CYP) Sensor Codes

These codes relate to the cylinder position sensor, used in some Honda models for misfire detection and other functions.

P1381 – Cylinder Position (CYP) Sensor Intermittent Interruption: Signals an intermittent signal issue with the CYP sensor.
P1382 – Cylinder Position (CYP) Sensor No Signal: Indicates no signal from the CYP sensor.

Air Pump Malfunction Code (Extended)

P1410 – Air Pump Malfunction: Another code indicating air pump malfunction.

Air Pump Electric Current Sensor Codes

P1415 – Air Pump Electric Current Sensor Circuit Low Voltage: Points to a low voltage issue in the air pump electric current sensor circuit.
P1416 – Air Pump Electric Current Sensor Circuit High Voltage: Indicates a high voltage issue in the air pump electric current sensor circuit.

NOx Adsorptive Catalyst System Efficiency Code

P1420 – Nox Adsorptive Catalyst System Efficiency Below Threshold: Indicates that the NOx adsorptive catalyst system efficiency is below the required threshold (relevant for some diesel or lean-burn gasoline Honda models).

Motor Drive Module (MDM) Codes (Hybrid System Related)

These codes are related to the Motor Drive Module (MDM) in Honda hybrid vehicles.

P1438 – Motor Drive Module (MDM) Overheating Signal Circuit: Points to an overheating signal circuit issue in the MDM.
P1438 – Motor Drive Module (MDM) Overheating: Indicates MDM overheating.
P1439 – Motor Drive Module (MDM) Short Circuit Sensor Problem: Points to a short circuit sensor problem in the MDM.
P1439 – Motor Drive Module (MDM) Short Circuit: Indicates MDM short circuit.

IMA System Problem Code (Hybrid System Related)

P1440 – IMA System Problem: General code indicating a problem within the Integrated Motor Assist (IMA) system in Honda hybrids.

Bypass Control Problem Code

P1445 – Bypass Control Problem: Indicates a problem with a bypass control system, potentially related to emissions or cooling.

Battery Module Overheating and Related Codes (Hybrid System Related)

These codes relate to battery module overheating and related issues in Honda hybrid vehicles.

P1448 – P1449 Battery Module Overheating: Codes indicating battery module overheating.
P1449 – Battery Cell Overheating: Indicates battery cell overheating.
P1449 – Battery Module Individual Voltage Input Deviation: Signals deviation in individual voltage input within the battery module.
P1449 – Battery Module Deterioration: Indicates battery module deterioration.
P1449 – Battery Module Deviation: Another code indicating battery module deviation.

Fuel Tank Pressure (FTP) Sensor Range/Performance Code (Extended)

P1454 – Fuel Tank Pressure (FTP) Sensor Range/Performance Problem: Another code indicating FTP sensor range/performance issues.

Evaporative Emissions (EVAP) Control System Leakage Codes (Extended)

P1456 – Evaporative Emissions (EVAP) Control System Leakage (Fuel Tank System): Specifies EVAP system leakage in the fuel tank system.
P1457 – Evaporative Emissions (EVAP) Control System Leakage (EVAP Canister System): Specifies EVAP system leakage in the EVAP canister system.
P1459 – Evaporative Emission (EVAP) Purge Flow Switch Malfunction: Points to a malfunction in the EVAP purge flow switch.

Exhaust Gas Recirculation (EGR) Valve Insufficient Lift and Position Sensor Codes (Extended)

P1491 – Exhaust Gas Recirculation (EGR) Valve Insufficient Lift: Another code indicating insufficient EGR valve lift.
P1486 – Cooling System Malfunction: Another code indicating cooling system malfunction.
P1491 – Exhaust Gas Recirculation (EGR) Valve Insufficient Lift: Another code indicating insufficient EGR valve lift.
P1498 – Exhaust Gas Recirculation (EGR) Valve Position Sensor Circuit High Voltage: Another code indicating high voltage in the EGR valve position sensor circuit.

Positive Crankcase Ventilation (PCV) Air Leakage Code

P1505 – Positive Crankcase Ventilation (PCV) Air Leakage: Indicates air leakage in the PCV system.

Idle Air Control Valve (IACV) Circuit Malfunction/Failure Codes

P1508 – P1519 Idle Air Control Valve (IACV) Circuit Malfunction: Codes indicating malfunction in the IACV circuit.
P1509 – Idle Air Control Valve (IACV) Circuit Failure: Indicates IACV circuit failure.

Brake Booster Pressure Sensor Codes

These codes relate to the brake booster pressure sensor, relevant for vehicles with electric brake boosters.

P1522 – Brake Booster Pressure Sensor Circuit Low Voltage: Points to a low voltage issue in the brake booster pressure sensor circuit.
P1523 – Brake Booster Pressure Sensor Circuit High Voltage: Indicates a high voltage issue in the brake booster pressure sensor circuit.
P1524 – Brake Booster Pressure Sensor Range/Performance Problem: Suggests the brake booster pressure sensor is providing inaccurate readings or is malfunctioning.

Climate Control Unit Signal Circuit Codes

P1541 – Climate Control Unit Signal Circuit Low Voltage: Points to a low voltage issue in the climate control unit signal circuit.
P1542 – Climate Control Unit Signal Circuit High Voltage: Indicates a high voltage issue in the climate control unit signal circuit.

Motor Commutation Signal Problem Code (Hybrid System Related)

P1565 – Motor Commutation Signal Problem: Indicates a problem with the motor commutation signal in a hybrid system.

Battery Module Individual Voltage Input and Temperature Signal Circuit Problem Codes (Hybrid System Related)

P1568 – Battery Module Individual Voltage Input Problem: Indicates a problem with individual voltage input to the battery module in a hybrid system.
P1568 – Battery Module Temperature Signal Circuit Problem: Indicates a temperature signal circuit problem in the battery module of a hybrid system.
P1568 – Battery Cell Temperature Signal Circuit Problem: Indicates a temperature signal circuit problem in the battery cell of a hybrid system.

Motor Drive Module (MDM) Temperature and Voltage Signal Circuit Codes (Hybrid System Related)

P1572 – Motor Drive Module (MDM) Temperature Signal Circuit Low Input: Points to a low input issue in the MDM temperature signal circuit.
P1572 – Motor Drive Module (MDM) Temperature Signal Circuit High Input: Indicates a high input issue in the MDM temperature signal circuit.
P1576 – Motor Drive Module (MDM) Voltge Signal Circuit Low Input: Points to a low input issue in the MDM voltage signal circuit.

High Voltage Detection Signal Circuit Problem Code (Hybrid System Related)

P1577 – High Voltage Detection Signal Circuit Problem: Indicates a problem with the high voltage detection signal circuit in a hybrid system.

Battery Current Circuit Problem Code (Hybrid System Related)

P1580 – Battery Current Circuit Problem: Indicates a problem with the battery current circuit in a hybrid system.

Motor Power Inverter (MPI) Module Current Signal Circuit Codes (Hybrid System Related)

P1581 – Motor Power Inverter (MPI) Module Current Signal Circuit Low Input: Points to a low input issue in the MPI module current signal circuit.
P1581 – Motor Power Inverter (MPI) Module Current Signal Circuit High Input: Indicates a high input issue in the MPI module current signal circuit.
P1581 – Motor Power Inverter (MPI) Module Current Signal Circuit Problem: General code indicating a problem in the MPI module current signal circuit.

Motor Current U, V, W Phase Signal Circuit Codes (Hybrid System Related)

P1582 – Motor Current U Phase Signal Circuit Low Input: Points to a low input issue in the motor current U phase signal circuit.
P1582 – Motor Current U Phase Signal Circuit High Input: Indicates a high input issue in the motor current U phase signal circuit.
P1583 – Motor Current V Phase Signal Circuit Low Input: Points to a low input issue in the motor current V phase signal circuit.
P1583 – Motor Current V Phase Signal Circuit High Input: Indicates a high input issue in the motor current V phase signal circuit.
P1584 – Motor Current W Phase Signal Circuit Low Input: Points to a low input issue in the motor current W phase signal circuit.
P1584 – Motor Current W Phase Signal Circuit High Input: Indicates a high input issue in the motor current W phase signal circuit.

Motor Current Signal Circuit Problem Code (Hybrid System Related)

P1585 – Motor Current Signal Circuit Problem: General code indicating a problem in the motor current signal circuit.

Motor Power Inverter (MPI) Module Current Signal/Battery Current Signal Circuit Problem Code (Hybrid System Related)

P1586 – Motor Power Inverter (MPI) Module Current Signal/Battery Current Signal Circuit Problem: Indicates a problem involving both MPI module current signal and battery current signal circuits.

Engine Control Module (ECM)/Powertrain Control Module (PCM) Internal Circuit Malfunction Code

P1607 – Engine Control Module (ECM)/Powertrain Control Module (PCM) Internal Circuit Malfunction: Indicates an internal circuit malfunction within the ECM/PCM.

Transmission Control Module Code

P1630 – Transmission Control Module: General code indicating a problem with the Transmission Control Module (TCM).

Battery Condition Monitor (BCM) Module Problem Code

P1635 – Battery Condition Monitor (BCM) Module Proble: General code indicating a problem with the Battery Condition Monitor (BCM) module.

MOTB Signal Circuit Malfunction Code

P1639 – MOTB Signal Circuit Malfunction: Indicates a malfunction in the MOTB (likely Motor Throttle Body) signal circuit.

ACTTRQ Motor Torque Signal Circuit Codes (Hybrid System Related)

P1640 – ACTTRQ Motor Torque Signal Circuit Low Input: Points to a low input issue in the ACTTRQ (Actual Torque Request) motor torque signal circuit.
P1641 – ACTTRQ Motor Torque Signal Circuit High Input: Indicates a high input issue in the ACTTRQ motor torque signal circuit.

QBATT Battery Signal Circuit Codes (Hybrid System Related)

P1642 – QBATT Battery Signal Circuit Low Input: Points to a low input issue in the QBATT (Battery Current) signal circuit.
P1643 – QBATT Battery Signal Circuit High Input: Indicates a high input issue in the QBATT signal circuit.

MOTFSA, MOTFSB, MOTSTB Signal Malfunction Codes (Hybrid System Related)

P1644 – MOTFSA Signal Malfunction: Indicates a malfunction in the MOTFSA (Motor Field Strength A) signal.
P1645 – MOTFSB Signal Malfunction: Indicates a malfunction in the MOTFSB (Motor Field Strength B) signal.
P1646 – MOTSTB Signal Malfunction: Indicates a malfunction in the MOTSTB (Motor Stator Temperature B) signal.

Power Command Signal Circuit Codes

P1647 – Power Command Signal Circuit Low Input: Points to a low input issue in the power command signal circuit.
P1647 – Power Command Signal Circuit High Input: Indicates a high input issue in the power command signal circuit.

Engine Torque Signal Circuit Codes

P1647 – Engine Torque Signal Circuit Low Input: Points to a low input issue in the engine torque signal circuit.
P1647 – Engine Torque Signal Circuit High Input: Indicates a high input issue in the engine torque signal circuit.

Mode Signal Circuit 1 and 2 Problem Codes

P1647 – Mode Signal Circuit 1 Low Input: Points to a low input issue in mode signal circuit 1.
P1647 – Mode Signal Circuit 1 High Input: Indicates a high input issue in mode signal circuit 1.
P1647 – Mode Signal Circuit 2 Problem: General code indicating a problem in mode signal circuit 2.

Engine Speed Signal Circuit Problem Code

P1647 – Engine Speed Signal Circuit Problem: General code indicating a problem in the engine speed signal circuit.

Battery Condition Monitor (BCM) Module and Motor Control Module (MCM) Communication Signal Circuit Problem Codes (Hybrid System Related)

P1648 – Battery Condition Monitor (BCM) Module Communication Signal Circuit Problem: Indicates a communication signal circuit problem with the BCM module.
P1648 – Motor Control Module (MCM) Communication Signal Circuit Problem: Indicates a communication signal circuit problem with the Motor Control Module (MCM).

CVT-FI TMA/TMB Signal Line Failure Code (CVT Specific)

P1655 – CVT-FI TMA/TMB Signal Line Failure: Indicates a signal line failure related to CVT-FI (CVT Fluid Indicator) TMA/TMB.

PCM-toVTM-4 Control Unit Communications Circuit Problem Code (VTM-4 System Related)

P1656 – Problem in PCM-toVTM-4 Control Unit Communications Circuit: Indicates a communication problem between the PCM and the VTM-4 (Variable Torque Management 4-Wheel Drive) control unit (relevant for Honda AWD vehicles).

A/T-FI Data Line Failure/TCM – ECM Halt Code

P1660 – A/T-FI Data Line Failure/TCM – ECM Halt: Indicates a data line failure related to A/T-FI (Automatic Transmission Fluid Indicator) or a TCM-ECM halt.

FPTDR Signal Line Failure Code

P1676 P1678 FPTDR Signal Line Failure: Codes indicating a signal line failure related to FPTDR (Fuel Pump Transistor Drive Relay).

RSCD Signal Circuit Malfunction Code

P1679 – RSCD Signal Circuit Malfunction: Indicates a malfunction in the RSCD (likely Ride Stability Control Device) signal circuit.

A/T FI Signal A and B Circuit Codes

P1681 – A/T FI Signal A Cicuit Low Voltage: Points to a low voltage issue in A/T FI (Automatic Transmission Fluid Indicator) Signal A circuit.
P1682 – A/T FI Signal A Circuit High Voltage: Indicates a high voltage issue in A/T FI Signal A circuit.
P1686 – A/T FI Signal B Circuit Low Voltage: Points to a low voltage issue in A/T FI Signal B circuit.
P1687 – A/T FI Signal B Circuit High Voltage: Indicates a high voltage issue in A/T FI Signal B circuit.

Throttle Valve Default and Return Spring Performance Problem Codes

P1683 – Throttle Valve Default Position Spring Performance Problem: Indicates a performance problem with the throttle valve default position spring.
P1684 – Throttle Valve Return Spring Performance Problem: Indicates a performance problem with the throttle valve return spring.

Shift Control System Problem Codes (Extended – Detailed Shift Solenoid Issues)

These codes provide more detailed information about specific shift solenoid valve issues within the automatic transmission.

P1730 – Problem in Shift Control System: Shift Solenoid Valve A and D Stuck OFF Shift Solenoid Valve B Stuck ON Shift Valves A, B, and D Stuck: Detailed description of a specific shift control system problem involving multiple shift solenoids.
P1731 – Problem in Shift Control System: Shift Solenoid Valve E Stuck ON Shift Valve E Stuck A/T Clutch Pressure Control Solenoid Valve A Stuck OFF: Detailed description of another specific shift control system problem.
P1732 – Problem in Shift Control System: Shift Solenoid Valve B and C Stuck ON Shift Valves B and C Stuck: Detailed description of a shift control system problem involving shift solenoids B and C.
P1733 – Problem in Shift Control System: Shift Solenoid Valve D Stuck ON Shift Valve D Stuck A/T Clutch Pressure Control Solenoid Valve C Stuck OFF: Detailed description of a shift control system problem involving shift solenoid D and A/T clutch pressure control solenoid C.
P1734 – Problem in Shift Control System: Shift Solenoid Valves B and C Stuck ON Shift Valves B and C Stuck: Repeated code, likely a duplicate of P1732.

Clutch Pressure Switch Circuit Problem Codes (Extended)

P1738 – Problem in 2nd Clutch Pressure Switch Circuit: Indicates a problem in the 2nd clutch pressure switch circuit.
P1739 – Problem in 3rd Clutch Pressure Switch Circuit: Indicates a problem in the 3rd clutch pressure switch circuit.
P1740 – Problem in 4th Clutch Pressure Switch Circuit: Indicates a problem in the 4th clutch pressure switch circuit.

Mechanical Problem in Hydraulic Control System Codes

P1750 – Mechanical Problem in Hydraulic Control System of A/T Clutch Pressure Control Solenoid Valve Assemblies A and B, or Problem in the Hydraulic Control System: Indicates a mechanical problem in the hydraulic control system related to specific solenoid valve assemblies or a general hydraulic system issue.
P1751 – Mechanical Problem in Hydraulic Control System of Shift Solenoid Valve B and A/T Clutch Pressure Control Solenoid Valves A and B, or Problem in the Hydraulic Control System: Similar to P1750, but specifying different solenoid valves.

Torque Converter Clutch Solenoid Valve Circuit Problem Codes (Extended)

P1753 – Problem in Torque Converter Clutch Solenoid Valve Circuit: Another code indicating a problem in the torque converter clutch solenoid valve circuit.
P1751 P1768 Problem in Torque Converter Clutch Solenoid Valve B Circuit: Codes indicating a problem in the torque converter clutch solenoid valve B circuit.

A/T Clutch Pressure Control Solenoid Valve B Circuit Problem Code (Extended)

P1773 – Problem in A/T Clutch Pressure Control Solenoid Valve B Circuit: Another code indicating a problem in the A/T clutch pressure control solenoid valve B circuit.

Throttle Position (TP) Sensor Circuit Malfunction Code (Extended)

P1790 – Throttle Position (TP) Sensor Circuit Malfunction: Another code indicating a malfunction in the TP sensor circuit.

Vehicle Speed Sensor (VSS) Range/Performance Problem Code (Extended)

P1791 – Vehicle Speed Sensor (VSS) Range/Performance Problem: Another code indicating VSS range/performance issues.

Engine Coolant Temperature (ECT) Sensor Circuit Problem Code (Extended)

P1792 – Problem in Engine Coolant Temperature (ECT) Sensor Circuit: Another code indicating a problem in the ECT sensor circuit.

Manifold Absolute Pressure Sensor Circuit Code (Extended)

P1793 – Manifold Absolute Pressure Sensor Circuit: Another code indicating a problem in the MAP sensor circuit.

CVT Speed Change, Pulley Pressure, and Start Clutch Control Valve Assembly Circuit Problem Codes (CVT Specific – Extended)

P1870 – Problem in CVT Speed Change Control Valve Assembly Circuit: Indicates a problem in the CVT speed change control valve assembly circuit.
P1873 – Problem in CVT Pulley Pressure Control Valve Assembly Circuit: Indicates a problem in the CVT pulley pressure control valve assembly circuit.
P1879 – Problem in CVT Start Clutch Pressure Control Valve Assembly Circuit: Indicates a problem in the CVT start clutch pressure control valve assembly circuit.
P1894 – CVT Speed Change Control Valve Circuit: Another code related to the CVT speed change control valve circuit.
P1895 – CVT Pulley Pressure Control Valve Circuit: Another code related to the CVT pulley pressure control valve circuit.

Inhibitor Solenoid Circuit Problem Code

P1882 – Problem in Inhibitor Solenoid Circuit: Indicates a problem in the inhibitor solenoid circuit (likely related to transmission or starting system).

Secondary Gear Speed Sensor 2 Circuit Malfunction Code

P1884 – Secondary Gear Speed Sensor 2 Circuit Malfunction: Indicates a malfunction in the secondary gear speed sensor 2 circuit.

CVT Drive and Driven Pulley Speed Sensor Circuit Codes (CVT Specific)

P1885 – CVT Drive Pulley Speed Sensor Circuit: Indicates a problem in the CVT drive pulley speed sensor circuit.
P1886 – CVT Driven Pulley Speed Sensor Circuit: Indicates a problem in the CVT driven pulley speed sensor circuit.

CVT Speed Sensor Code (CVT Specific – Extended)

P1888 – CVT Speed Sensor: General code indicating a problem with a CVT speed sensor.
P1889 – Problem in CVT Speed Sensor 2 Circuit: Indicates a problem in CVT speed sensor 2 circuit.

Shift Control System Code (Extended)

P1890 – Shift Control System: Another general code indicating a problem in the shift control system.

Start Clutch System Problem Code

P1891 – Problem in Start Clutch System: Indicates a problem in the start clutch system (likely related to CVT or automatic transmission).

Throttle Actuator System Malfunction and Related Codes

These codes relate to the electronic throttle control system.

P2101 – Throttle Actuator System Malfunction: Indicates a general malfunction in the throttle actuator system.
P2108 – Throttle Actuator Control Module Problem: Points to a problem with the throttle actuator control module.
P2118 – Throttle Actuator Current Range/Performance Problem: Suggests the throttle actuator current is out of range or not performing as expected.
P2176 – Throttle Actuator Control System Idle Position Not Learned: Signals that the throttle actuator control system has not learned the idle position, potentially after a reset or component replacement.
P2552 – Throttle Actuator Control Module Relay Malfunction: Points to a malfunction in the throttle actuator control module relay.

Accelerator Pedal Position (APP) Sensor Codes

These codes relate to the accelerator pedal position sensors, which provide input to the electronic throttle control system.

P2122 – Accelerator Pedal Position (APP) Sensor 1 (Throttle Position Sensor D) Circuit Low Voltage: Points to a low voltage issue in APP sensor 1 circuit.
P2123 – Accelerator Pedal Position (APP) Sensor 1 (Throttle Position Sensor D) Circuit High Voltage: Indicates a high voltage issue in APP sensor 1 circuit.
P2127 – Accelerator Pedal Position (APP) Sensor 2 (Throttle Position Sensor E) Circuit Low Voltage: Points to a low voltage issue in APP sensor 2 circuit.
P2128 – Accelerator Pedal Position (APP) Sensor 2 (Throttle Position Sensor E) Circuit High Voltage: Indicates a high voltage issue in APP sensor 2 circuit.
P2135 – Throttle Position (TP) Sensor 1/2 Incorrect Voltage Correlation: Signals an incorrect voltage correlation between TP sensors 1 and 2.
P2138 – Accelerator Pedal Position (APP) Sensor 1/2 (Throttle Position Sensor D/E) Incorrect Voltage Correlation: Signals an incorrect voltage correlation between APP sensors 1 and 2.

Intake Air System Leak Code

P2279 – Intake Air System Leak: Indicates a leak in the intake air system, which can cause lean running conditions.

Exhaust Gas Recirculation (EGR) System Range/Performance Code (Extended)

P2413 – Exhaust Gas Recirculation (EGR) System Range/Performance Problem: Another code indicating EGR system range/performance issues.

Evaporative Emission (EVAP) System Vent Shut Valve Close Malfunction Code

P2422 – Evaporative Emission (EVAP) System Vent Shut Valve Close Malfunction: Indicates a malfunction preventing the EVAP vent shut valve from closing properly.

System Communication Error Codes (U Codes)

These codes indicate communication problems within the vehicle’s network.

U0073 – FCAN Malfunction (Bus-off): Indicates a malfunction in the FCAN (likely Fault-Tolerant Controller Area Network) bus, causing a bus-off condition.
U0107 – Lost Communication With Throttle Actuator Control Module: Signals a loss of communication with the throttle actuator control module.
U0121 – FCAN Malfunction (TCS-PCM): Indicates a malfunction in the FCAN bus related to communication between the TCS (Traction Control System) and PCM.
U0155 – FCAN Malfunction (Gauge Control Module-ECM/PCM): Indicates a malfunction in the FCAN bus related to communication between the Gauge Control Module and ECM/PCM.

Diagnosing Honda Engine Codes OBD2

When your Honda’s check engine light illuminates, the first step is to retrieve the OBD2 code using a scanner. These scanners are user-friendly and plug into the OBD2 port, typically located under the dashboard on the driver’s side.

Steps for Basic Diagnosis:

Retrieve the Code: Use an OBD2 scanner to read the stored code(s). Note down all codes present.
Understand the Code: Refer to a reliable source like this guide or a Honda repair manual to understand the meaning of each code.
Visual Inspection: Check for obvious issues like loose gas cap (for EVAP codes), disconnected hoses, or damaged wiring around the sensor indicated by the code.
Basic Troubleshooting (If Comfortable): For sensor-related codes, you might consider checking sensor connections or, if you have experience, testing sensor voltage or resistance. However, proceed with caution and consult repair manuals for specific procedures.
Clear the Code (Optional): Some scanners allow you to clear the code. If the issue was minor or intermittent, the light might stay off. However, if the problem persists, the light will return, and clearing the code doesn’t fix the underlying issue.

When to Seek Professional Help:

Unfamiliar Codes: If you are unsure about the meaning of the code or how to proceed.
Complex Codes: Transmission codes (P0700-P0986, P1630, P1705-P1895, P2769, P2770) and hybrid system codes often require specialized diagnostic tools and expertise.
Persistent Check Engine Light: If the check engine light returns after basic troubleshooting or clearing the code.
Driveability Issues: If you experience symptoms like rough running, stalling, loss of power, or unusual noises along with the check engine light.

Maintaining Your Honda to Prevent Engine Codes

Preventative maintenance is key to minimizing engine problems and avoiding check engine lights. Regular servicing according to Honda’s recommended schedule is essential. This includes:

Oil Changes: Regular oil changes with the correct type of oil are crucial for engine lubrication and longevity.
Air Filter Replacement: A clean air filter ensures proper airflow to the engine.
Spark Plug Replacement: Spark plugs need periodic replacement to ensure efficient ignition.
Coolant Flushes: Regular coolant flushes maintain the cooling system’s effectiveness.
Fuel System Maintenance: Using quality fuel and considering fuel system cleaners periodically can help prevent fuel system issues.
Regular Inspections: Routine inspections can catch potential problems early before they trigger engine codes.

Conclusion

Understanding Honda engine codes OBD2 empowers you to be a more informed car owner and take proactive steps in maintaining your vehicle. While this guide provides a comprehensive overview of common Honda OBD2 codes, it’s important to remember that diagnosis can be complex. When in doubt, consulting a qualified and experienced automotive technician is always the best course of action to ensure accurate diagnosis and proper repair, keeping your Honda running smoothly for years to come.