You may have come across the terms “OBD” or “OBDII” when reading about connected cars and vehicle diagnostics. These features are integral to modern vehicle computer systems and have a history that’s perhaps less known. This article provides a comprehensive overview of OBDII and a timeline of its development, answering the question: what does OBD2 mean?
What is OBD (On-Board Diagnostics)?
On-Board Diagnostics (OBD) refers to the automotive electronic system that provides vehicle self-diagnosis and reporting capabilities for repair technicians. An OBD system allows technicians to access subsystem information to monitor vehicle performance and diagnose repair needs efficiently.
OBD is the standard protocol used in most light-duty vehicles to retrieve diagnostic information. This information is generated by the Engine Control Units (ECUs), often referred to as the “brain” or computer of the vehicle. These ECUs manage and monitor various aspects of the car’s operation.
Alt text: OBD2 port pinout diagram illustrating the connector layout and pin assignments for vehicle diagnostics.
Why is OBD2 Important?
OBD is a cornerstone of vehicle telematics and fleet management because it enables the measurement and management of vehicle health and driving behavior. Understanding what OBD2 means in practical terms highlights its value.
Thanks to OBD, fleets can:
- Track wear and tear trends to identify vehicle parts that degrade faster than others.
- Diagnose vehicle issues proactively, often before breakdowns occur, supporting preventative maintenance.
- Measure driving behavior metrics such as speed, idling time, and more, promoting safer and more efficient driving practices.
Where is the OBD2 Port Located?
In a typical passenger vehicle, the OBD2 port is usually located on the underside of the dashboard on the driver’s side. Depending on the vehicle type, the port may have a 16-pin, 6-pin, or 9-pin configuration, with the 16-pin being the most common standard for OBD2.
Alt text: A mechanic uses an OBD2 scanner connected to a car’s diagnostic port to read vehicle data for maintenance.
OBD vs. OBD2: What’s the Difference?
OBDII is essentially the second generation of OBD, or OBD I. OBD-I systems were often external add-ons, whereas OBDII is integrated directly into the vehicle’s architecture. The original OBD systems were used until OBDII was developed in the early 1990s, marking a significant advancement in vehicle diagnostics.
History of OBD2: A Timeline
The history of on-board diagnostics dates back to the 1960s. Several organizations played a crucial role in establishing the standard, including the California Air Resources Board (CARB), the Society of Automotive Engineers (SAE), the International Organization for Standardization (ISO), and the Environmental Protection Agency (EPA).
Before standardization, each manufacturer developed proprietary systems. Diagnostic tools from each manufacturer, and sometimes even across different models from the same manufacturer, had unique connector types, electronic interface requirements, and custom codes for reporting issues. This lack of uniformity highlighted the need for a standardized approach, leading to the development of OBDII.
Key Milestones in OBD History
1968 — Volkswagen introduced the first computer-based OBD system with scanning capabilities.
1978 — Datsun (now Nissan) implemented a simple OBD system, though with limited and non-standardized capabilities.
1979 — The Society of Automotive Engineers (SAE) recommended a standardized diagnostic connector and a set of diagnostic test signals, aiming to bring uniformity to the industry.
1980 — General Motors (GM) introduced a proprietary interface and protocol capable of providing engine diagnostics via an RS-232 interface, or more simply, by flashing the Check Engine Light.
1988 — Standardization of on-board diagnostics began in the late 1980s following the 1988 SAE recommendation, which called for a standard connector and diagnostic set, paving the way for OBD standardization.
1991 — The state of California mandated that all vehicles have some form of basic on-board diagnostics. This initial mandate is known as OBD I.
1994 — California required that all vehicles sold in the state from 1996 onwards must have OBD as recommended by SAE, now termed OBDII. This was essential for widespread emissions testing and enhanced vehicle diagnostics. OBDII included a set of standardized Diagnostic Trouble Codes (DTCs).
1996 — OBD-II became mandatory for all cars manufactured in the United States, marking a significant step towards standardized vehicle diagnostics.
2001 — EOBD, the European version of OBD, became mandatory for all gasoline vehicles in the European Union, extending the reach of standardized diagnostics globally.
2003 — EOBD became mandatory for all diesel vehicles in the EU, further solidifying the European standard for vehicle diagnostics.
2008 — Starting in 2008, all vehicles in the United States were required to implement OBDII via a Controller Area Network (CAN), as specified in ISO standard 15765-4, enhancing data communication speeds and reliability.
What Data Can You Access from OBD2?
OBDII provides access to both status information and Diagnostic Trouble Codes (DTCs) for:
- Powertrain (engine and transmission systems)
- Emissions control systems
Additionally, the following vehicle information is accessible through OBDII:
- Vehicle Identification Number (VIN)
- Calibration Identification Number
- Ignition counter
- Emissions control system counters
When a car is taken to a service center, a mechanic can connect a scan tool to the OBD port to read fault codes and pinpoint problems. This capability means mechanics can accurately diagnose issues, quickly inspect vehicles, and address malfunctions before they escalate into serious problems.
Examples of OBD2 Data:
Mode 1 (Vehicle Information):
- PID 12 — Engine RPM
- PID 13 — Vehicle Speed
Mode 3 (Fault Codes: P= Powertrain, C= Chassis, B= Body, U= Network):
- P0201 — Injector Circuit Malfunction – Cylinder 1
- P0217 — Engine Overtemperature Condition
- P0219 — Engine Overspeed Condition
- C0128 — Brake Fluid Low Circuit
- C0710 — Steering Position Malfunction
- B1671 — Battery Module Voltage Out of Range
- U2021 — Invalid/Faulty Data Received
Understanding what OBD2 means involves knowing the types of data it provides, which is crucial for vehicle maintenance and performance monitoring.
OBD and Telematics
The presence of OBDII allows telematics devices to seamlessly process information such as engine RPM, vehicle speed, fault codes, fuel consumption, and much more. A telematics device can use this data to determine trip start and end times, instances of over-revving, speeding, excessive idling, fuel usage, and other critical parameters. All this information is then uploaded to a software interface, enabling fleet management teams to monitor vehicle usage and performance effectively.
Alt text: A telematics device plugged into a vehicle’s OBD2 port, illustrating data collection for fleet management.
Given the multitude of OBD protocols, not all telematics solutions are designed to work with every type of vehicle currently on the road. Geotab telematics overcomes this challenge by translating diagnostic codes from various makes and models, including electric vehicles.
With the OBD-II port, connecting a fleet tracking solution to your vehicle is quick and straightforward. For Geotab, setup can be completed in under five minutes.
If your vehicle or truck does not have a standard OBDII port, adapters can be used. In any case, the installation process is typically rapid and does not require special tools or professional installer assistance.
What is WWH-OBD?
WWH-OBD stands for World Wide Harmonized On-Board Diagnostics. It is an international standard used for vehicle diagnostics, implemented by the United Nations as part of the Global Technical Regulation (GTR) mandate. WWH-OBD includes monitoring vehicle data such as emissions output and engine fault codes, expanding upon the capabilities of OBDII.
Advantages of WWH-OBD
Adopting WWH-OBD offers several technical advantages:
Access to More Data Types
Current OBDII Parameter IDs (PIDs) used in Mode 1 are limited to one byte, meaning only up to 255 unique data types are available. WWH-OBD allows for expansion of PIDs, potentially across other OBD-II modes that have transitioned to WWH through UDS modes. Adopting WWH standards allows for more data and offers scalability for future data needs.
More Detailed Fault Information
Another advantage of WWH-OBD is the expanded information contained within a fault code. Currently, OBDII uses a two-byte Diagnostic Trouble Code (DTC) to indicate when a fault has occurred (e.g., P0070 indicates “Ambient Air Temperature Sensor ‘A’ Circuit Malfunction”).
Unified Diagnostic Services (UDS) expands the 2-byte DTC into a 3-byte DTC, where the third byte indicates the “failure mode.” This failure mode is similar to the Failure Mode Indicator (FMI) used in the J1939 protocol. For example, previously in OBDII, you might have several fault codes for similar sensor issues:
- P0070 Ambient Air Temperature Sensor Circuit
- P0071 Ambient Air Temperature Sensor Range/Performance
- P0072 Ambient Air Temperature Sensor Circuit Low Input
- P0073 Ambient Air Temperature Sensor Circuit High Input
- P0074 Ambient Air Temperature Sensor Circuit Intermittent
With WWH-OBD, these are consolidated into a single code, P0070, with 5 different failure modes indicated in the third byte of the DTC. For instance, P0071 now becomes P0070-1C, providing more granular detail about the nature of the fault.
WWH-OBD also offers more fault information such as severity/class and status. Severity indicates how urgently the fault needs attention, while the fault class indicates the fault’s category according to GTR specifications. Additionally, the fault status indicates if it is pending, confirmed, or if testing for the fault in the current driving cycle is complete.
In summary, WWH-OBD expands the current OBDII framework to offer even richer diagnostic information to the user.
Geotab Supports WWH-OBD
Geotab has already implemented the WWH-OBD protocol in our firmware. Geotab employs a sophisticated protocol detection system that safely examines what is available in the vehicle to determine if OBD-II or WWH-OBD is available (in some cases, both are).
At Geotab, we are continuously enhancing our firmware to expand the information available to our customers. We have already begun supporting 3-byte DTC information and continue to add more fault information generated by vehicles. When new information becomes available through OBDII or WWH-OBD (such as new PIDs or fault data), or if a new protocol is implemented in vehicles, Geotab prioritizes quickly and accurately adding it to the firmware. We then immediately push new firmware updates to our devices over the cloud, ensuring our customers always benefit from the most comprehensive data available from their vehicles.
Growth Beyond OBDII
OBDII contains 10 standard modes for accessing diagnostic information required by emissions standards. However, these 10 modes have proven insufficient for the growing data needs of modern vehicles.
Over the years since OBDII’s implementation, several UDS modes have been developed to enrich available data. Each vehicle manufacturer uses proprietary PIDs and implements them using additional UDS modes. Information not essential for OBDII data (such as odometer readings and seat belt usage) has become accessible through UDS modes.
UDS contains more than 20 additional modes beyond the current 10 standard modes available through OBDII, signifying a substantial increase in available data. WWH-OBD seeks to incorporate UDS modes with OBDII to enrich diagnostic data while maintaining a standardized process, bridging the gap between legacy OBDII and the evolving needs of vehicle diagnostics.
Conclusion
In the expanding world of IoT, the OBD port remains crucial for vehicle health, safety, and sustainability. While the number and variety of connected devices for vehicles increase, not all devices provide and track the same information. Moreover, compatibility and security can vary across devices.
Given the multitude of OBD protocols, not all telematics solutions are designed to function universally across vehicle types. Effective telematics solutions must be capable of understanding and translating a comprehensive set of vehicle diagnostic codes. Understanding what OBD2 means is just the beginning; the future of vehicle diagnostics is heading towards more comprehensive and harmonized standards like WWH-OBD, ensuring richer data for better vehicle management and maintenance.
