You may have come across the terms “OBD” or “OBDII” when reading about connected vehicles and devices like Geotab GO. These features are integral parts of modern car computer systems and have a history that’s more interesting than you might think. In this article, as your auto repair expert from techcarusa.com, we’ll provide a detailed overview of what is OBD2 and explore the evolution of on-board diagnostics.
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 to monitor vehicle performance and diagnose repair needs efficiently.
OBD is the standard protocol utilized in most light-duty vehicles to retrieve diagnostic information. This data is generated by Engine Control Units (ECUs), often referred to as engine control modules or the “brain” of your vehicle.
Alt: OBD2 port pinout diagram, showing connector pin assignments for vehicle diagnostics.
The Importance of OBD in Modern Vehicles
OBD is a critical component in vehicle 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 vehicle parts that are wearing out faster than expected.
- Proactive Vehicle Management: Instantly diagnose vehicle issues before they escalate, facilitating proactive rather than reactive maintenance.
- Measure Driving Behavior: Monitor driving habits, including speed, idling time, and more, to optimize performance and safety.
Alt: Location of OBD2 port under the dashboard of a car, driver’s side, for accessing vehicle diagnostics.
Locating the OBD2 Port in Your Vehicle
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 connector being the most common in modern cars.
OBD vs. OBD2: What’s the Difference?
Simply put, OBD2 is the second generation of OBD, or OBD I. Early OBD systems were often external to the car’s console, whereas OBD2 is integrated directly into the vehicle’s architecture. OBD was the standard until OBD2 was developed in the early 1990s, bringing significant improvements and standardization.
A Brief History of OBD2 Development
The history of on-board diagnostics dates back to the 1960s. Several organizations played a crucial role in laying the groundwork for the standard we know today, 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, vehicle manufacturers developed their own proprietary diagnostic systems. Each manufacturer’s tools, and sometimes even different models from the same manufacturer, had unique connector types, electronic interface requirements, and custom codes for reporting 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 scanning capabilities.
1978 — Datsun (now Nissan) launched a simple, non-standardized OBD system with limited capabilities.
1979 — The Society of Automotive Engineers (SAE) recommended a standardized diagnostic connector and a set of diagnostic test signals to improve consistency in vehicle servicing.
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 to indicate fault codes.
1988 — Standardization of on-board diagnostics began in the late 1980s, following the 1988 SAE recommendation that called for a standard connector and diagnostic set.
1991 — The state of California mandated that all vehicles sold within the state must have some form of basic on-board diagnostics, known as OBD I.
1994 — California mandated OBD compliance for all vehicles sold in the state from 1996 onwards, based on SAE recommendations. This enhanced standard, known as OBDII, was implemented to facilitate widespread emissions testing and included a set of standardized Diagnostic Trouble Codes (DTCs).
1996 — OBD-II became mandatory for all cars manufactured for sale in the United States, marking a significant step towards standardized vehicle diagnostics.
2001 — EOBD (European On-Board Diagnostics), the European version of OBD, became mandatory for all gasoline vehicles in the European Union, further extending the reach of standardized diagnostics.
2003 — EOBD was extended to become mandatory for all diesel vehicles in the EU, ensuring comprehensive diagnostic coverage across vehicle types.
2008 — Starting in 2008, all vehicles in the United States were required to implement OBDII using a Controller Area Network (CAN) as specified in ISO standard 15765-4, enhancing data communication speeds and reliability.
Data Accessible Through OBD2
OBD2 provides access to a wealth of status information and Diagnostic Trouble Codes (DTCs) related to:
- Powertrain: Engine and transmission systems, allowing for detailed monitoring of performance and potential issues.
- Emission Control Systems: Ensuring vehicles meet environmental regulations by tracking the performance of emission-related components.
In addition to these critical systems, the following vehicle information is also accessible via OBD2:
- Vehicle Identification Number (VIN): Uniquely identifies the vehicle.
- Calibration Identification Number: Software version identification for ECUs.
- Ignition Counter: Tracks the number of engine start cycles.
- Emission Control System Counters: Monitors the performance and usage of emission control systems.
When you take your car to a repair shop for servicing, a mechanic can connect a scan tool to the OBD port to read fault codes and pinpoint problems. This capability allows mechanics to accurately diagnose malfunctions, inspect vehicles quickly, and address issues before they become major concerns.
Examples of OBD2 Data:
Mode 1 (Vehicle Information): Provides real-time data parameters.
- PID 12 — Engine RPM: Revolutions Per Minute, indicating engine speed.
- PID 13 — Vehicle Speed: Current speed of the vehicle.
Mode 3 (Fault Codes: P= Powertrain, C= Chassis, B= Body, U= Network): Reports diagnostic trouble codes.
- P0201 — Injector Circuit Malfunction – Cylinder 1: Indicates an issue with the fuel injector in cylinder 1.
- P0217 — Engine Overtemperature Condition: Signals that the engine is overheating.
- P0219 — Engine Overspeed Condition: Indicates the engine is running too fast.
- C0128 — Low Brake Fluid Circuit: Warns about low brake fluid level.
- C0710 — Steering Position Malfunction: Indicates a problem with the steering position sensor.
- B1671 — Battery Module Voltage Out of Range: Signals a voltage issue with the battery module.
- U2021 — Invalid/Faulty Data Received: Indicates communication errors within the vehicle’s network.
Alt: Mechanic using an OBD2 scanner to diagnose a vehicle, reading diagnostic trouble codes from the OBDII port.
OBD and Telematics Systems
The widespread adoption of OBD2 has paved the way for advanced vehicle telematics. Telematics devices leverage the OBD2 port to silently process information such as engine RPM, vehicle speed, fault codes, fuel consumption, and much more. These devices 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 and vehicle owners to monitor vehicle usage and performance effectively.
Given the multitude of OBD protocols, not all telematics solutions are designed to work with every vehicle type currently on the road. Geotab telematics overcomes this challenge by intelligently translating diagnostic codes from various makes and models, including electric vehicles, ensuring broad compatibility and accurate data interpretation.
Connecting a fleet tracking solution to your vehicle is quick and easy thanks to the OBD-II port. For instance, Geotab devices can be set up in under five minutes, offering plug-and-play simplicity.
For vehicles or trucks without a standard OBDII port, adapters can be used to bridge the connection. In any case, the installation process remains fast and does not require specialized tools or professional installer assistance.
What is WWH-OBD?
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 aims to standardize and enhance vehicle diagnostics globally, focusing on monitoring vehicle data like emissions output and engine fault codes with greater detail and consistency.
Advantages of WWH-OBD
Adopting WWH-OBD offers several technical advantages:
Expanded Data Access
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 expands PID capabilities, potentially applicable to other OBD-II modes transitioning to WWH via Unified Diagnostic Services (UDS) modes. This adaptation allows for more data points and future expansion possibilities, providing a more comprehensive view of vehicle operation.
More Detailed Fault Information
Another key enhancement of WWH-OBD is the increased detail in fault reporting. OBDII currently uses a two-byte Diagnostic Trouble Code (DTC) to indicate a fault (e.g., P0070 indicates “Ambient Air Temperature Sensor ‘A’ Circuit Malfunction”).
Unified Diagnostic Services (UDS) expands the DTC from 2 bytes to 3 bytes. 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, in OBDII, you might see 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-OBD, these are consolidated under a single code, P0070, with different failure modes indicated in the third byte of the DTC. For instance, P0071 might become P0070-1C, streamlining fault codes and providing more specific diagnostic information.
WWH-OBD also offers additional fault details such as severity/class and status. Severity indicates the urgency of addressing the fault, while the class categorizes the fault according to GTR specifications. Fault status indicates if the fault is pending, confirmed, or if testing for the fault is completed in the current driving cycle, offering a richer understanding of vehicle issues.
In summary, WWH-OBD extends the current OBDII framework to provide users with even more diagnostic insight and precision.
Geotab’s Support for 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 whether OBD-II or WWH-OBD (and in some cases, both) are accessible.
At Geotab, we are continuously enhancing our firmware to expand the information our customers receive. We have already begun supporting 3-byte DTC information and continue to add more detail about vehicle-generated faults. 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 our firmware. We then immediately deploy the new firmware to our devices over-the-air, ensuring our customers always benefit from the most comprehensive data available.
Growth Beyond OBDII with UDS
OBDII includes 10 standard modes to access the diagnostic information required for emissions standards. However, these 10 modes have proven to be insufficient for the growing data needs of modern vehicles.
Since the implementation 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 initially required through OBDII data (like odometer readings and seat belt usage) became accessible through UDS modes.
UDS includes more than 20 additional modes beyond the current 10 standard modes available through OBDII, meaning significantly more information is potentially accessible. WWH-OBD seeks to integrate UDS modes with OBDII to enrich diagnostic data while maintaining a standardized process.
Conclusion
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 are increasing, 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 essential to choose telematics solutions capable of understanding and translating a comprehensive set of vehicle diagnostic codes. Robust telematics systems should be able to effectively leverage OBD and WWH-OBD to provide users with accurate and actionable vehicle insights. Understanding what is OBD2 and its evolution is crucial for anyone involved in vehicle maintenance, fleet management, or automotive technology.
