You may have come across the terms “OBD” or “OBDII” when reading about connected vehicles and devices like the Geotab GO. These features are part of the onboard computers in cars and have a history that is perhaps not widely known. In this article, we provide an overview of OBDII and a timeline of its development.
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 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 essentially the computers or the “brains” of the vehicle.
Why is OBD So Important?
OBD is a crucial component of telematics and fleet management because it enables 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 maintenance management.
- Measure driving behavior, including speed, idling time, and much more.
Where is the OBDII Port Located?
In a typical passenger vehicle, the OBDII port is located on the underside of the dashboard on the driver’s side of the car. Depending on the type of vehicle, the port may have a 16-pin, 6-pin, or 9-pin configuration.
OBD vs. OBDII: What’s the Difference?
Simply put, OBDII is 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 system was used until OBDII was developed in the early 1990s.
A Brief 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 proprietary systems. Each manufacturer’s tools (and sometimes models within the same manufacturer) had their own connector types and electronic interface requirements. They also used their own custom codes to report issues.
Here are some key milestones in the history of OBD:
- 1968: Volkswagen introduced the first computer-based OBD system with scan capability. This marked an early step towards electronic vehicle diagnostics.
- 1978: Datsun (now Nissan) introduced a simple OBD system, albeit with limited and non-standardized capabilities. This demonstrated a growing industry interest in onboard diagnostics.
- 1979: The Society of Automotive Engineers (SAE) recommended a standardized diagnostic connector and a set of diagnostic test signals. This was a crucial step towards industry-wide standardization.
- 1980: General Motors (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. This showed early proprietary implementations before open standards.
- 1988: Standardization of on-board diagnostics gained momentum following the 1988 SAE recommendation, which called for a standard connector and diagnostic set. This was a pivotal moment leading to OBD standards.
- 1991: The state of California mandated that all vehicles have some form of basic on-board diagnostics. This became known as OBD I and marked the first regulatory push for OBD.
- 1994: 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 was a major regulatory driver for OBDII adoption.
- 1996: OBD-II became mandatory for all cars manufactured in the United States. This federal mandate solidified OBDII as the standard for vehicle diagnostics in the US market.
- 2001: EOBD (European version of OBD) became mandatory for all gasoline vehicles in the European Union. This expanded OBD standardization beyond North America.
- 2003: EOBD became mandatory for all diesel vehicles in the EU. This further broadened EOBD coverage in Europe.
- 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. This update brought OBDII into the modern CAN bus era.
What Data Can You Access from OBD2?
OBDII provides access to status information and Diagnostic Trouble Codes (DTCs) for:
- Powertrain (engine and transmission)
- Emissions control systems
In addition, the following vehicle information can be accessed via OBDII:
- Vehicle Identification Number (VIN)
- Calibration Identification Number
- Ignition Counter
- Emissions control system counters
When you take your car to a service shop, 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, quickly inspect the vehicle, and fix any issues before they become major problems.
Examples of OBDII 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
OBD 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 times, over-revving, speeding, excessive idling, fuel usage, etc. All of this information is uploaded to a software interface, allowing fleet management teams to monitor vehicle usage and performance.
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, you can quickly and easily connect a fleet tracking solution to your vehicle. In the case of Geotab, setup can be completed 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 quick and does not require any special tools or the assistance of a professional installer.
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.
Benefits of WWH-OBD
Here are the benefits 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, which means only up to 255 unique data types are available. The expansion of PIDs could also apply to other OBD-II modes that have moved to WWH via UDS modes. Adopting WWH standards allows for more data and provides the possibility of future expansion.
More Detailed Fault Data
Another benefit 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 the ambient air temperature sensor “A” has a general electrical fault).
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 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 3rd byte of the DTC. For example, P0071 now becomes P0070-1C.
WWH also offers more fault information such as severity/class and status. Severity will indicate how soon the fault needs to be reviewed, while the fault class will indicate which group the fault belongs to as per GTR specifications. Additionally, the fault status will indicate if it is pending, confirmed, or if the test for this fault has been completed in the current driving cycle.
In summary, WWH-OBD expands upon the current OBDII framework to provide even more diagnostic information to the user.
Geotab is Compatible with 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 figure 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 obtain. We have already begun supporting 3-byte DTC information and continue to add more fault information generated in vehicles. When new information becomes available through 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-air so that our customers always get the most benefit from their devices.
Growing Beyond OBDII
OBDII contains 10 standard modes to get the diagnostic information required by emissions regulations. The issue is that these 10 modes have not been sufficient.
Over the years since OBDII implementation, several UDS modes have been developed to enrich available data. Each vehicle manufacturer uses their own PIDs and implements them using additional UDS modes. Information that was not required through OBDII data (like 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, seeking 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 is increasing, not all devices give and track the same information. Furthermore, 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.
