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 your car’s on-board computers and have a history that many are unaware of. This article provides a detailed overview of OBDII and a timeline of its development, tailored for the English-speaking audience seeking to understand “what is an OBD2”.
Understanding OBD: On-Board Diagnostics Explained
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 performance and diagnose 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), often referred to as the car’s computer or brain, within a vehicle.
Why is OBD 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 and individual car owners can:
- Track wear and tear trends: Identify which vehicle parts are wearing out faster than others, facilitating preventative maintenance.
- Diagnose vehicle issues proactively: Instantly identify potential problems before they escalate, supporting a proactive maintenance approach rather than reactive repairs.
- Measure driving behavior: Monitor speed, idling time, and other driving habits to improve efficiency and safety.
Locating the OBDII Port in Your Vehicle
In a typical passenger vehicle, the OBDII 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. The 16-pin port is the most common type in modern vehicles.
OBD vs. OBDII: What’s the Difference?
Simply put, OBDII is the second generation of OBD, or OBD I. OBD-I was initially an externally connected system to a car’s console, whereas OBDII is integrated directly into the vehicle itself. The original OBD system was used until OBDII was developed in the early 1990s.
The key differences can be summarized as:
- Standardization: OBD-I was largely manufacturer-specific, with different connectors and diagnostic codes. OBDII is highly standardized across the automotive industry.
- Data Capabilities: OBDII offers a significantly expanded range of diagnostic data and parameters compared to OBD-I.
- Integration: OBDII is integrated into the vehicle’s computer system, providing real-time access to a wide array of data.
The History of OBDII: A Timeline of Development
The history of on-board diagnostics dates back to the 1960s. Several organizations played a foundational 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).
It’s important to note that before standardization, automakers created their own proprietary systems. Each manufacturer’s tools (and sometimes even different models from the same manufacturer) had unique connector types and electronic interface requirements. They also used custom codes to report issues, making diagnostics complex and manufacturer-specific.
Here are key milestones in the history of OBD:
1968 — Volkswagen introduces the first computer-based OBD system with scan capability. This marked an early step towards electronic vehicle diagnostics.
1978 — Datsun (now Nissan) presents a simple OBD system with limited, non-standardized capabilities. This shows the growing trend towards on-board diagnostics, though still in proprietary forms.
1979 — The Society of Automotive Engineers (SAE) recommends a standardized diagnostic connector and a set of diagnostic test signals. This was a crucial step towards industry-wide standardization.
1980 — General Motors (GM) introduces 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 demonstrates early manufacturer-specific OBD implementations.
1988 — Standardization of on-board diagnostics gains momentum following the 1988 SAE recommendation, calling for a standard connector and diagnostic set. This paved the way for OBD-II.
1991 — The state of California mandates that all vehicles have some form of basic on-board diagnostics. This regulation is known as OBD-I and was a major push towards standardization.
1994 — California Air Resources Board (CARB) mandates that all vehicles sold in the state from 1996 onwards must have OBD compliant with SAE recommendations, now termed OBDII. This was to facilitate widespread emissions testing. OBDII included a set of standardized Diagnostic Trouble Codes (DTCs).
1996 — OBD-II becomes mandatory for all cars manufactured in the United States. This was a landmark year for standardized vehicle diagnostics.
2001 — EOBD (European version of OBD) becomes mandatory for all gasoline vehicles in the European Union. This extended the reach of standardized diagnostics to Europe.
2003 — EOBD becomes mandatory for all diesel vehicles in the EU. Further expanding the mandate to include diesel vehicles.
2008 — Starting in 2008, all vehicles in the United States are required to implement OBDII via a Controller Area Network (CAN), as specified in ISO standard 15765-4. This reflects advancements in vehicle communication protocols.
An OBDII port typically located beneath the steering wheel column in a vehicle.
What Data Can You Access from OBDII?
OBDII provides access to a wealth of information related to vehicle status and Diagnostic Trouble Codes (DTCs) for:
- Powertrain (Engine and Transmission): Monitoring engine performance, transmission health, and related systems.
- Emissions Control Systems: Ensuring compliance with emissions standards and identifying issues affecting emissions.
In addition, the following vehicle information is accessible through OBDII:
- Vehicle Identification Number (VIN): Unique identifier for the vehicle.
- Calibration Identification Number: Software version and calibration details.
- Ignition Counter: Number of engine starts.
- Emissions Control System Counters: Data related to emissions system performance.
When you take your car to a service center, a mechanic can connect to the OBD port with a scan tool, read fault codes, and quickly pinpoint problems. This means mechanics can accurately diagnose issues, inspect vehicles efficiently, and fix faults before they become major problems.
Examples of OBDII Data:
Mode 1 (Vehicle Information): This mode provides real-time data and sensor readings.
- PID 12 — Engine RPM: Revolutions Per Minute of the engine.
- PID 13 — Vehicle Speed: Current speed of the vehicle.
Mode 3 (Trouble Codes: P= Powertrain, C= Chassis, B= Body, U= Network): These codes indicate specific problems within the vehicle systems.
- P0201 — Injector Circuit Malfunction – Cylinder 1: Problem with the fuel injector in cylinder 1.
- P0217 — Engine Overtemp Condition: Engine overheating.
- P0219 — Engine Overspeed Condition: Engine exceeding safe RPM limits.
- C0128 — Low Brake Fluid Circuit: Low brake fluid level detected.
- C0710 — Steering Position Malfunction: Issue with the steering position sensor.
- B1671 — Battery Module Voltage Out of Range: Battery voltage outside of normal operating range.
- U2021 — Invalid/Faulty Data Received: Communication error within the vehicle network.
A mechanic using an OBDII scanner tool to diagnose a vehicle.
OBD and Telematics: Connecting Vehicles for Data and Insights
The presence of OBDII allows telematics devices to seamlessly 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 this information is uploaded to a software interface, enabling fleet management teams and car owners to monitor vehicle usage and performance.
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 different makes and models, including electric vehicles.
With the OBD-II port, connecting a fleet tracking or vehicle monitoring solution to your vehicle is quick and easy. 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 any case, the installation process is generally fast and does not require special tools or professional installer assistance.
What is WWH-OBD? The Next Evolution in Diagnostics
WWH-OBD stands for World Wide Harmonized On-Board Diagnostics. It is an international standard for vehicle diagnostics, implemented by the United Nations as part of the Global Technical Regulation (GTR) mandate. WWH-OBD includes monitoring of vehicle data such as emissions output and engine fault codes, aiming for a globally unified diagnostic approach.
Advantages of WWH-OBD: Enhanced Diagnostic Capabilities
Moving to WWH-OBD offers several technical advantages:
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. WWH-OBD expands PIDs, potentially also applying to other OBD-II modes transitioned to WWH through Unified Diagnostic Services (UDS) modes. Adopting WWH standards allows for more data availability and future expansion possibilities.
More Detailed Fault Information
Another key advantage of WWH 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 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 separate fault codes like:
- 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 can be 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.
WWH also offers additional fault information such as severity/class and status. Severity indicates how urgently the fault needs attention, while the fault class categorizes the fault according to GTR specifications. Furthermore, fault status indicates if it is pending, confirmed, or if testing for this fault is completed within the current driving cycle.
In summary, WWH-OBD expands the current OBDII framework to provide users with even richer diagnostic information.
Geotab’s Support for WWH-OBD
Geotab has already implemented the WWH protocol in our firmware. Geotab employs a sophisticated protocol detection system, securely examining what is available in the vehicle to determine if OBD-II or WWH is available (in some cases, both are).
At Geotab, we are continuously improving our firmware to expand the insights our customers gain. 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 vehicles, Geotab prioritizes quickly and accurately adding it to the firmware. We then immediately deploy the new firmware to our devices over-the-air, ensuring our customers always benefit from the most comprehensive data from their devices.
Growing Beyond OBDII: Embracing UDS
OBDII contains 10 standard modes to obtain the diagnostic information required by emissions regulations. However, these 10 modes have become insufficient for the increasing complexity of vehicle systems and the demand for richer data.
Over the years since OBDII implementation, various UDS modes have been developed to enrich available data. Each vehicle manufacturer uses their own PIDs and implements them using additional UDS modes. Information not required through OBDII data (such as odometer readings and seat belt usage) became available through UDS modes.
UDS contains more than 20 additional modes beyond the current 10 standard modes available through OBDII, meaning UDS holds a greater wealth of information. WWH-OBD seeks to incorporate UDS modes with OBDII to enrich available diagnostic data while maintaining a standardized process.
Conclusion: The Enduring Importance of OBD
In the growing world of IoT, the OBD port remains vital for vehicle health, safety, and sustainability. While the number and variety of connected devices for vehicles increases, not all devices provide and track the same information. Furthermore, compatibility and security can vary across devices.
Given the multitude of OBD protocols, it’s crucial to choose telematics solutions that can understand and translate a comprehensive set of vehicle diagnostic codes. Robust telematics solutions like Geotab ensure compatibility across a wide range of vehicles, providing consistent and reliable data for effective vehicle management and insights. As vehicle technology evolves, OBD and its advancements like WWH-OBD will continue to play a central role in vehicle diagnostics and connected car technologies.
