You may have come across the terms “OBD” or “OBDII” when reading about connected vehicles and automotive diagnostics. These features are integral parts of modern car onboard computer systems, and they have a history that’s quite insightful. In this article, we will provide a detailed overview of OBDII and explore its crucial role in vehicle maintenance and telematics.
Understanding OBD: On-Board Diagnostics
On-Board Diagnostics (OBD) is the term for 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 performance and diagnose repair needs efficiently.
OBD is the standardized protocol used in most light-duty vehicles to retrieve diagnostic information. This information is generated by the Engine Control Units (ECUs), often referred to as the “brain” or computer of the vehicle.
The Significance of OBDII
OBD is a cornerstone of vehicle telematics and fleet management because it enables the measurement and management of vehicle health and driving behavior.
Thanks to OBD, fleets can achieve:
- Wear Trend Tracking: Monitor wear patterns to identify vehicle parts that degrade faster than expected, allowing for preventative maintenance.
- Instant Vehicle Issue Diagnosis: Diagnose vehicle problems proactively, often before they escalate, facilitating a proactive maintenance approach rather than reactive repairs.
- Driving Behavior Measurement: Measure driving habits, including speed, idling time, and other metrics, to improve driver performance and vehicle efficiency.
Locating the OBDII Port
In a typical passenger vehicle, the OBDII 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 connector is the most common, standardized by OBDII.
OBD vs. OBDII: What’s the Difference?
OBDII is essentially the second generation of OBD, or OBD I. OBD-I systems were initially external add-ons, while OBDII is now integrated into the vehicle itself. OBD I was the standard until OBDII was developed in the early 1990s, marking a significant advancement in vehicle diagnostics.
The Evolution of OBDII: A Historical Timeline
The history of on-board diagnostics dates back to the 1960s. Several organizations played a crucial 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).
Before standardization, vehicle manufacturers developed proprietary systems. Diagnostic tools from each manufacturer, and sometimes even across different models from the same manufacturer, had unique connector types and electronic interface requirements. They also used custom codes to report issues, making vehicle repair and diagnostics complex and inefficient.
Key Milestones in OBD History
1968 — Volkswagen introduces the first computer-based OBD system with scanning capabilities, a pioneering step in automotive diagnostics.
1978 — Datsun (now Nissan) presents a simple OBD system, though with limited and non-standardized capabilities, highlighting early efforts in onboard diagnostics.
1979 — The Society of Automotive Engineers (SAE) recommends a standardized diagnostic connector and a uniform set of diagnostic test signals, aiming to streamline vehicle servicing.
1980 — General Motors (GM) introduces a proprietary interface and protocol capable of providing engine diagnostics via an RS-232 interface or, more simply, by flashing the Check Engine Light, marking a move towards more accessible diagnostics.
1988 — Standardization of on-board diagnostics gains momentum following the SAE’s 1988 recommendation for a standard connector and diagnostic set, setting the stage for OBDII.
1991 — The state of California mandates that all vehicles must include some form of basic on-board diagnostics, known as OBD I, to monitor emissions-related components.
1994 — California mandates OBD compliance for all vehicles sold in the state from 1996 onwards, based on SAE recommendations. This enhanced standard, OBDII, is designed to facilitate widespread emissions testing and includes a set of standardized Diagnostic Trouble Codes (DTCs).
1996 — OBD-II becomes mandatory for all cars manufactured for sale in the United States, marking a significant regulatory milestone for standardized vehicle diagnostics.
2001 — EOBD (European On-Board Diagnostics), the European version of OBD, becomes mandatory for all gasoline vehicles in the European Union, extending standardized diagnostics globally.
2003 — EOBD is extended to become mandatory for all diesel vehicles in the EU, further enhancing diagnostic capabilities across vehicle types.
2008 — Starting in 2008, all vehicles in the United States are required to implement OBDII using a Controller Area Network (CAN), as specified in ISO standard 15765-4, improving data communication speed and reliability.
Accessible Data via OBDII
OBDII provides access to crucial status information and Diagnostic Trouble Codes (DTCs) for key vehicle systems:
- Powertrain: Engine and transmission performance data.
- Emission Control Systems: Monitoring of components related to vehicle emissions.
Furthermore, OBDII allows access to important vehicle identification and system data:
- Vehicle Identification Number (VIN): Unique vehicle identifier.
- Calibration Identification Number: Software version identifier for the ECU.
- Ignition Counter: Number of engine starts.
- Emission Control System Counters: Data related to the performance of emission control systems.
When you take your car for servicing, a mechanic connects a scan tool to the OBD port to read fault codes and pinpoint issues. This process allows mechanics to accurately diagnose problems, inspect vehicles quickly, and address faults before they become major concerns.
Examples of OBDII Data:
Mode 1 (Vehicle Information – Live Data Parameters):
- PID 12 — Engine RPM (Revolutions Per Minute)
- PID 13 — Vehicle Speed
Mode 3 (Diagnostic Trouble Codes – Fault Codes):
- P0201 — Injector Circuit Malfunction – Cylinder 1 (P= Powertrain)
- P0217 — Engine Overtemperature Condition
- P0219 — Engine Overspeed Condition
- C0128 — Brake Fluid Low Circuit (C= Chassis)
- C0710 — Steering Position Malfunction
- B1671 — Battery Module Voltage Out of Range (B= Body)
- U2021 — Invalid/Faulty Data Received (U= Network/Communication)
These codes are crucial for mechanics to quickly identify and resolve vehicle issues, ensuring efficient repairs and maintenance.
OBD and Telematics Integration
The presence of OBDII 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, instances of over-revving, speeding, excessive idling, fuel usage, etc. All this information is then uploaded to a software interface, empowering 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 currently on the road. Geotab telematics overcomes this challenge by translating diagnostic codes from various makes and models, including electric vehicles.
With the standardized OBD-II port, connecting a fleet tracking solution to your vehicle is quick and straightforward. For instance, Geotab devices can be set up in under five minutes.
If your vehicle or truck lacks a standard OBDII port, an adapter can be used. In any case, the installation process remains rapid and does not require specialized tools or professional installer assistance.
WWH-OBD: Worldwide Harmonized On-Board 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. This standard includes monitoring vehicle data such as emissions output and engine fault codes, aiming for global consistency in vehicle diagnostics.
Advantages of WWH-OBD
Adopting WWH-OBD offers several technical advantages:
Enhanced Data Access
Current OBDII Parameter IDs (PIDs) in Mode 1 are limited to one byte, restricting the availability to only 255 unique data types. Expanding PIDs, as facilitated by WWH-OBD through Unified Diagnostic Services (UDS) modes, allows for significantly more data types. Adapting to WWH standards provides access to more extensive data and offers future scalability for increasingly complex vehicle systems.
More Detailed Fault Information
Another key advantage of WWH-OBD is the expanded detail in fault reporting. OBDII currently uses a two-byte Diagnostic Trouble Code (DTC) to indicate a fault (e.g., P0070 indicates a general electrical fault in the ambient air temperature sensor “A”).
Unified Diagnostic Services (UDS) expands the 2-byte DTC to 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, with OBDII, you might encounter several fault codes related to the ambient temperature sensor:
- 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 5 different failure modes indicated in the third byte of the DTC. For instance, P0071 now becomes P0070-1C.
WWH-OBD also provides additional fault information, such as severity/class and status. Severity indicates the urgency of addressing the fault, while the fault class categorizes the fault according to GTR specifications. Fault status indicates whether the fault is pending, confirmed, or if the test for this fault has been completed in the current driving cycle.
In essence, WWH-OBD expands the current OBDII framework to provide users with richer diagnostic information, leading to more precise and efficient vehicle servicing.
Geotab’s WWH-OBD Compatibility
Geotab has already implemented the WWH protocol in its firmware. Geotab employs a sophisticated protocol detection system to securely assess vehicle capabilities, determining whether OBD-II or WWH-OBD (or sometimes both) is available.
Geotab continuously enhances its firmware to broaden the insights available to its customers. Support for 3-byte DTC information has already been integrated, and efforts to incorporate more detailed fault information from vehicles are ongoing. When new information becomes available through OBDII or WWH-OBD (like a new PID or fault data), or if a new protocol is implemented in vehicles, Geotab prioritizes rapid and accurate integration into its firmware. New firmware updates are immediately deployed to devices over-the-air, ensuring customers always benefit from the latest diagnostic capabilities.
Expanding Beyond OBDII Limitations
OBDII includes 10 standard modes to retrieve diagnostic information required for emissions standards. However, these 10 modes have proven insufficient for the growing complexity of vehicle systems.
Since the introduction of OBDII, various UDS modes have been developed to enrich available data. Vehicle manufacturers utilize proprietary PIDs and implement them using additional UDS modes. Information not initially accessible through OBDII data, such as odometer readings and seat belt usage, has become available via UDS modes.
UDS encompasses over 20 additional modes beyond the standard 10 modes of OBDII, offering a significantly larger scope of information. WWH-OBD aims to integrate UDS modes with OBDII to enhance diagnostic data availability while maintaining a standardized process, bridging the gap and leveraging advanced diagnostic capabilities.
Conclusion
In the expanding realm of IoT, the OBD port remains vital for vehicle health, safety, and sustainability. While the number and types 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 crucial to choose telematics solutions capable of understanding and translating a comprehensive set of vehicle diagnostic codes. Robust telematics solutions ensure accurate vehicle data interpretation, regardless of the underlying OBD protocol, maximizing the benefits of connected vehicle technology for vehicle owners and fleet managers alike.
