You may have come across the terms “OBD” or “OBDII” when reading about connected vehicles and devices. These features are part of the on-board computers in cars and have a history that is not widely known. In this article, we will provide you with an overview of OBDII and a timeline of its development.
Understanding 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 in order to monitor performance and analyze repair needs.
OBD is the standard protocol used in most light-duty vehicles to retrieve vehicle diagnostic information. This information is generated by the Engine Control Units (ECUs), or engine control modules, within a vehicle. These are like the computers or the brain of the vehicle.
Alt text: OBDII port in a vehicle, typically located under the dashboard on the driver’s side, used for accessing vehicle diagnostic information.
Why is OBD2 Important?
OBD is a crucial component of telematics and fleet management because it allows for the measurement and management of vehicle health and driving behavior.
Thanks to OBD, fleets can:
- Track wear and tear trends and see which vehicle parts are wearing out faster than others.
- Instantly diagnose vehicle problems before they escalate, supporting proactive rather than reactive management.
- Measure driving behavior, speed, idling time, and much more.
Alt text: Fleet management dashboard interface displaying vehicle data and analytics derived from OBDII system, essential for monitoring fleet performance and maintenance.
Where is the OBD2 Port Located?
In a typical passenger vehicle, the OBD2 port is located on the underside of the dashboard on the driver’s side of the car. Depending on the vehicle type, the port may have a 16-pin, 6-pin, or 9-pin configuration. The 16-pin port is the most common for OBD2 systems in modern cars.
What is the Difference Between OBD and OBD2?
OBDII is, simply put, the second generation of OBD or OBD I. OBD I was initially connected externally to a car’s console, whereas OBDII is now integrated within the vehicle itself. The original OBD was in use until OBDII was developed in the early 1990s to provide a more standardized and comprehensive diagnostic system.
History of OBD2
The history of on-board diagnostics dates back to the 1960s. Several organizations laid the groundwork for 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).
It is important to note that before standardization, manufacturers created their own systems. Each manufacturer’s tools (and sometimes models from the same manufacturer) had their own connector type and electronic interface requirements. They also used their own custom codes to report issues. This lack of uniformity made vehicle diagnostics complex and inefficient.
Key Milestones in OBD History
1968 — Volkswagen introduced the first computer-based OBD system with scan capability, marking the beginning of computerized vehicle diagnostics.
1978 — Datsun presented a simple OBD system with limited, non-standardized capabilities, an early step towards on-board diagnostics but lacking industry standards.
1979 — The Society of Automotive Engineers (SAE) recommended a standardized diagnostic connector and a set of diagnostic test signals, pushing for uniformity in diagnostic interfaces.
1980 — GM introduced a proprietary interface and protocol capable of providing engine diagnostics through an RS-232 interface or, more simply, by flashing the check engine light, demonstrating early proprietary diagnostic approaches.
1988 — Standardization of on-board diagnostics arrived in the late 1980s following the SAE’s 1988 recommendation, which called for a standard connector and diagnostic set, a critical move towards OBD standardization.
1991 — The state of California required all vehicles to have some form of basic on-board diagnostics. This is known as OBD I, representing the first regulatory push for basic on-board diagnostic systems.
1994 — The state of California mandated that all vehicles sold in the state from 1996 onwards must have OBD as recommended by SAE, now termed OBDII, to enable widespread emissions testing. OBDII included a set of standardized Diagnostic Trouble Codes (DTCs). This regulation was pivotal for OBDII adoption.
1996 — OBD-II became mandatory for all cars manufactured in the United States, a landmark year making standardized OBDII systems a requirement across the US automotive industry.
2001 — EOBD (the European version of OBD) became mandatory for all gasoline vehicles in the European Union, expanding the reach of standardized diagnostics to Europe.
2003 — EOBD became mandatory for all diesel vehicles in the EU, completing the mandatory implementation of EOBD for all new vehicles in the European Union.
2008 — Starting in 2008, all vehicles in the United States are required to implement OBDII via a Controller Area Network, as specified in ISO standard 15765-4. This update mandated the communication protocol for OBDII systems.
Alt text: Timeline infographic illustrating the historical evolution of OBD systems from the 1960s to the 2000s, highlighting key milestones and advancements in OBD technology.
What Data Can You Access from OBD2?
OBD2 provides access to status information and Diagnostic Trouble Codes (DTCs) for:
- Powertrain (engine and transmission)
- Emission control systems
In addition, the following vehicle information can be accessed through OBD2:
- Vehicle Identification Number (VIN)
- Calibration Identification number
- Ignition counter
- Emission control system counters
When a car is taken to a service center for maintenance, a mechanic can connect to the OBD port with a scan tool, read the fault codes, and pinpoint the problem. This means mechanics can accurately diagnose faults, inspect the vehicle quickly, and fix any issues before they become major problems.
Examples:
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
OBD2 and Telematics
The presence of OBDII allows telematics devices to silently process information such as engine RPM, vehicle speed, fault codes, fuel consumption, and much more. The telematics device can use this information to determine trip start and end, over-revving, speeding, excessive idling, fuel consumption, etc. All of this information is uploaded to a software interface, enabling fleet management teams to monitor vehicle usage and performance effectively.
With 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 different makes and models, and even electric vehicles.
With the OBD-II port, a fleet tracking solution can be connected to your vehicle quickly and easily. In the case of Geotab, it can be set up in under five minutes.
If your vehicle or truck does not have a standard OBDII port, an adapter can be used instead. In either case, the installation process is fast and does not require any special tools or help from a professional installer.
Alt text: Automotive mechanic using an OBD2 scanner tool connected to a vehicle’s OBDII port to diagnose engine problems during a car service.
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, which includes monitoring vehicle data, such as emissions output and engine fault codes.
Advantages of WWH-OBD
Below are the advantages of moving to WWH in more technical terms:
Access to More Data Types
Currently, OBDII Parameter IDs (PIDs) used in Mode 1 are only one byte, meaning only up to 255 unique data types are available. The expansion of PIDs could also be applied to other OBD-II modes that have been carried over to WWH via UDS modes. Adapting WWH standards allows for more data availability and offers room for future expansion.
More Detailed Fault Data
Another advantage of WWH is the expansion of the information contained within a fault. 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 could have the following five faults:
- 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, these are all consolidated into one code P0070, with 5 different failure modes indicated in the third byte of the DTC. For example, P0071 now becomes P0070-1C.
WWH also provides more fault information such as severity/class and status. Severity will indicate how soon the fault should be reviewed, while the fault class will indicate which group the fault belongs to per GTR specifications. Furthermore, the fault status will indicate if it is pending, confirmed, or if the test for this fault has completed in the current driving cycle.
In summary, WWH-OBD expands upon the current OBDII framework to offer even more diagnostic information to the user.
Geotab Supports WWH-OBD
Geotab has already implemented the WWH protocol in our firmware. Geotab employs a complex protocol detection system, where we safely probe what is available on the vehicle, to find out if OBD-II or WWH is available (in some cases both are).
At Geotab, we are constantly improving our firmware to further expand the information our customers receive. We have already started supporting 3-byte DTC information and continue to add more fault information generated in vehicles. When new information becomes available via OBDII or WWH (such as a new PID or fault data), or if a new protocol is implemented in the vehicle, Geotab prioritizes quickly and accurately adding it to the firmware. We then immediately send the new firmware to our units over the cloud so our customers get the most benefit from their devices at all times.
Growing Beyond OBD2
OBDII contains 10 standard modes to get the diagnostic information required by emissions regulations. The problem is that these 10 modes have not been sufficient.
Over the years since OBDII implementation, several UDS modes have been developed to enrich the data available. Each vehicle manufacturer uses their own PIDs and implements them using additional UDS modes. Information that was not required through OBDII data (such as odometer and seat belt usage) became available through UDS modes.
The reality is that UDS contains over 20+ additional modes on top of the current 10 standard modes available through OBDII, meaning UDS has more information available. But that is where WWH-OBD comes in, which seeks to incorporate UDS modes with OBDII to enrich the data available for diagnostics, while still maintaining a standardized process.
Conclusion
In the growing world of IoT, the OBD port remains important for vehicle health, safety, and sustainability. While the number and variety of connected devices for vehicles are increasing, not all devices give and track the same information. Additionally, compatibility and security can vary from device to device.
With the multitude of OBD protocols, not all telematics solutions are designed to work with every type of vehicle currently on the road. Good telematics solutions should be able to understand and translate a comprehensive set of vehicle diagnostic codes to provide valuable insights and support for vehicle maintenance and management.
