You might have come across terms like “OBD” or “OBDII” when exploring connected vehicles and telematics devices. These features are integral to modern car computer systems and have a history that’s worth understanding. This article provides a comprehensive overview of OBDII and its evolution, focusing on its practical applications and benefits.
What is OBD (On-Board Diagnostics)?
On-Board Diagnostics (OBD) is the automotive electronic system that offers vehicle self-diagnosis and reporting capabilities to 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 data is generated by Engine Control Units (ECUs), often referred to as the “brain” or computer of the vehicle.
Why is OBD2 Important?
OBD2 plays a crucial role in vehicle telematics and fleet management because it enables the measurement and management of vehicle health and driving behavior.
Thanks to OBD2, fleets and vehicle owners can:
- Track Wear and Tear: Identify patterns of wear and determine which vehicle parts are degrading faster than expected.
- Proactive Diagnostics: Instantly diagnose vehicle problems before they escalate, facilitating proactive maintenance rather than reactive repairs.
- Measure Driving Behavior: Monitor driving habits, speed, idling time, and other parameters to improve efficiency and safety.
Where is the OBD2 Port Located?
In a typical passenger vehicle, the OBD2 port is usually located beneath 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 for OBD2 in modern cars.
OBD vs. OBD2: What’s the Difference?
OBD2 is simply the second generation of OBD, or OBD I. The original OBD was often externally connected to a car’s console, whereas OBD2 is integrated directly into the vehicle itself. OBD I was used until OBD2 was developed in the early 1990s to standardize and improve vehicle diagnostics.
The History of OBD2: A Timeline of Innovation
The history of on-board diagnostics dates back to the 1960s. Several organizations contributed to the development of 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, connector types, electronic interface requirements, and trouble codes varied significantly, even within the same manufacturer’s models.
Key Milestones in OBD History
1968 — Volkswagen introduces the first computer-based OBD system with scanning capabilities.
1978 — Datsun presents a basic OBD system with limited, non-standardized capabilities.
1979 — The Society of Automotive Engineers (SAE) recommends a standardized diagnostic connector and a set of diagnostic test signals.
1980 — GM launches a proprietary interface and protocol capable of providing engine diagnostics through an RS-232 interface or, more simply, by flashing the check engine light.
1988 — OBD standardization gains momentum in the late 1980s following the 1988 SAE recommendation for a standard connector and diagnostic set.
1991 — The state of California mandates that all vehicles must include some form of basic on-board diagnostics, known as OBD I.
1994 — California requires all vehicles sold in the state from 1996 onwards to feature OBD as recommended by SAE, now termed OBDII, to enable widespread emissions testing. OBDII includes a set of standardized Diagnostic Trouble Codes (DTCs).
1996 — OBD-II becomes mandatory for all cars manufactured in the United States.
2001 — EOBD (European version of OBD) becomes mandatory for all gasoline vehicles in the European Union.
2003 — EOBD becomes mandatory for all diesel vehicles in the EU.
2008 — From 2008, all vehicles in the United States are required to implement OBDII via a Controller Area Network, as specified in ISO standard 15765-4.
What Data Can You Access with OBD2?
OBD2 provides access to crucial status information and Diagnostic Trouble Codes (DTCs) for:
- Powertrain: Engine and transmission systems.
- Emissions Control Systems.
Furthermore, the following vehicle information is accessible through OBD2:
- Vehicle Identification Number (VIN)
- Calibration Identification Number
- Ignition Counter
- Emissions control system counters
When you take your car to a service center, a mechanic can connect a scan tool to the OBD port, read fault codes, and pinpoint problems. This capability allows mechanics to accurately diagnose issues, quickly inspect vehicles, and address faults before they become major concerns.
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
OBD2 and Telematics: Enhancing Fleet Management
The presence of OBD2 enables telematics devices to seamlessly process information such as engine RPM, vehicle speed, fault codes, fuel consumption, and much more. A telematics device uses this data to determine trip start and end times, over-revving, speeding, excessive idling, fuel usage, and other critical metrics. All this information is uploaded to a software interface, allowing fleet management teams to monitor vehicle usage and performance effectively.
Given the multitude of OBD protocols, not all telematics solutions are designed to work with every type of vehicle. Geotab telematics overcomes this challenge by translating diagnostic codes from various makes and models, including electric vehicles.
With the OBD-II port, integrating a fleet tracking solution into your vehicle is quick and straightforward. For instance, Geotab devices can be set up 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 fast and does not require specialized tools or professional installation assistance.
What is WWH-OBD? The Next Generation of Diagnostics
WWH-OBD stands for World Wide Harmonized On-Board Diagnostics. It is an international standard for vehicle diagnostics, developed by the United Nations as part of the Global Technical Regulation (GTR) mandate. WWH-OBD enhances vehicle data monitoring, including emissions output and engine fault codes, and aims to standardize diagnostic processes globally.
Advantages of WWH-OBD
Transitioning to WWH-OBD offers several technical advantages:
Expanded Data Access
Current OBDII Parameter IDs (PIDs) used in Mode 1 are limited to one byte, restricting the availability to 255 unique data types. WWH-OBD expands PIDs, potentially applicable to other OBD-II modes transitioning to WWH via UDS (Unified Diagnostic Services) modes. Adopting WWH standards allows for more data and future scalability.
More Detailed Fault Information
Another benefit of WWH is the expanded information within a fault code. Currently, OBDII uses a two-byte Diagnostic Trouble Code (DTC) to indicate a fault (e.g., P0070 indicates a general electrical fault with the ambient air temperature sensor “A”).
Unified Diagnostic Services (UDS) extends 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, several faults might exist:
- 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 consolidated into a single code, P0070, with 5 different failure modes indicated in the third byte of the DTC. For example, P0071 now becomes P0070-1C, providing more granular diagnostic detail.
WWH also offers additional fault information, such as severity/class and status. Severity indicates the urgency for addressing the fault, while the fault class categorizes the fault according to GTR specifications. Fault status indicates if a fault is pending, confirmed, or if testing for the fault is completed within the current driving cycle.
In essence, WWH-OBD enhances the current OBDII framework to provide users with richer diagnostic information.
Geotab Supports WWH-OBD
Geotab has already implemented the WWH protocol in our firmware. Geotab employs a sophisticated protocol detection system to securely examine vehicle communication and determine if OBD-II or WWH (or both) are available.
At Geotab, we are continuously improving our firmware to expand the information available to our customers. We have begun supporting 3-byte DTC information and continue to add more detailed fault data from vehicles. When new information becomes available through OBDII or WWH (such as new PIDs or fault data), or if a new protocol is implemented in vehicles, Geotab prioritizes rapid and accurate integration into our firmware. We then immediately deploy the updated firmware to our devices over-the-air, ensuring our customers always benefit from the most comprehensive data.
Growth Beyond OBDII
OBDII includes 10 standard modes for accessing diagnostic information required for emissions standards. However, these 10 modes have become insufficient for accessing the wealth of data available in modern vehicles.
Since the introduction of OBDII, 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 emission data (like odometer readings and seat belt usage) became accessible through UDS modes.
UDS encompasses over 20 additional modes beyond the 10 standard modes of OBDII, offering significantly more data. WWH-OBD aims to integrate UDS modes with OBDII to enrich diagnostic data while maintaining a standardized process, paving the way for more comprehensive vehicle diagnostics.
Conclusion: The Enduring Importance of OBD
In the expanding world of IoT, the OBD port remains vital 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 diversity of OBD protocols, effective telematics solutions must be capable of understanding and translating a broad range of vehicle diagnostic codes. As vehicle technology evolves, OBD and its advancements like WWH-OBD will continue to be crucial for vehicle diagnostics, fleet management, and ensuring vehicles operate efficiently and safely.
