You may have come across the terms “OBD” or “OBDII” when reading about connected vehicles and devices. These features are integral to modern car onboard computers and have a history that is not widely known. As an auto repair expert at obd2global.com, this article provides a comprehensive overview of OBDII and a timeline of its development, focusing on OBD2 car diagnostics.
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 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 Engine Control Units (ECUs), also known as engine control modules, within a vehicle. These ECUs are essentially the computers or “brains” of your car.
Alt text: Locating the OBDII port in a vehicle, typically found under the dashboard on the driver’s side, for accessing car diagnostic information.
Why is OBD2 Car Diagnostics Important?
OBD is a critical component of telematics and fleet management because it allows for the measurement and management of vehicle health and driving behavior. Understanding OBD2 car diagnostics is essential for proactive vehicle maintenance and efficient fleet operations.
Thanks to OBD, fleets can:
- Track wear and tear trends to identify which vehicle parts are degrading faster than others.
- Instantly diagnose vehicle issues before they escalate, enabling proactive rather than reactive management.
- Measure driving behavior, including speed, idling time, and much more, for performance optimization and safety improvements.
Where is the OBDII Port Located?
In a typical passenger vehicle, the OBDII port is usually located under the dashboard on the driver’s side of the car. Depending on the vehicle type, the port may have a 16-pin, 6-pin, or 9-pin configuration. This standardized location makes OBD2 car diagnostics accessible for technicians and devices.
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 was used until OBDII was developed in the early 1990s. OBDII represents a significant advancement in OBD2 car diagnostics by offering greater standardization and accessibility.
History of OBDII and Car Diagnostics
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). The evolution of OBD2 car diagnostics is a story of increasing standardization and capability.
It’s important to note that before standardization, manufacturers created their own proprietary systems. Each manufacturer’s tools (and sometimes even models from the same manufacturer) had their own connector types and electronic interface requirements. They also used custom codes to report problems, making OBD2 car diagnostics a complex and fragmented field.
Key Milestones in OBD History
1968 — Volkswagen introduced the first computer-based OBD system with scanning capability.
1978 — Datsun introduced a simple OBD system with limited, non-standardized capabilities.
1979 — The Society of Automotive Engineers (SAE) recommended a standardized diagnostic connector and a set of diagnostic test signals.
1980 — 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.
1988 — Standardization for on-board diagnostics arrived in the late 1980s following the 1988 SAE recommendation calling for a standard connector and diagnostic set. This marked a turning point for OBD2 car diagnostics.
1991 — The state of California mandated that all vehicles have some form of basic on-board diagnostics. This became known as OBD I.
1994 — The state of 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 standardized set of Diagnostic Trouble Codes (DTCs). This was a major step towards standardized OBD2 car diagnostics.
1996 — OBD-II became mandatory for all cars manufactured in the United States.
2001 — EOBD (the European version of OBD) became mandatory for all gasoline vehicles in the European Union.
2003 — EOBD became mandatory for all diesel vehicles in the EU.
2008 — Starting in 2008, all vehicles in the United States were required to implement OBDII via a Controller Area Network, as specified in ISO standard 15765-4. This further enhanced the capabilities of OBD2 car diagnostics.
Alt text: Timeline illustrating the evolution of OBD systems from OBD-I to OBD-II and WWH-OBD, highlighting key years and advancements in car diagnostic technology.
What Data Can Be Accessed Through OBDII?
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 for comprehensive OBD2 car diagnostics:
- Vehicle Identification Number (VIN)
- Calibration Identification Number
- Ignition counter
- Emissions control system counters
When you take your car to a service center for maintenance, 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, inspect vehicles quickly, and fix any issues before they become major problems. OBD2 car diagnostics empowers faster and more accurate vehicle servicing.
Examples:
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 — Low Brake Fluid 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 consumption, etc. All this information is uploaded to a software interface, allowing fleet management teams to monitor vehicle usage and performance. OBD2 car diagnostics data is crucial for effective telematics applications.
With the multitude of OBD protocols, not all telematics solutions are designed to work with every type of vehicle currently available. Geotab telematics overcomes this challenge by translating diagnostic codes from different makes and models, and even electric vehicles. Geotab’s advanced telematics solutions leverage OBD2 car diagnostics data from a wide range of 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 any case, the installation process is fast and does not require any special tools or the help of a professional installer. This ease of use underscores the accessibility of OBD2 car diagnostics.
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. WWH-OBD represents the next generation of OBD2 car diagnostics, offering enhanced capabilities and data access.
Advantages of WWH-OBD
Below are the advantages of moving to WWH in more technical terms:
Access to More Data Types
Currently, OBDII PIDs (Parameter IDs) used in Mode 1 are only one byte, meaning only up to 255 unique data types are available. The expansion of PIDs could also be applied to other OBD-II modes that have moved to WWH via UDS modes. Adopting WWH standards allows for more data availability and provides the potential for future expansion in OBD2 car diagnostics.
More Detailed Fault Data
Another benefit of WWH is the expansion of 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). WWH-OBD enhances OBD2 car diagnostics by providing richer fault information.
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 could 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 third byte of the DTC. For example, P0071 now becomes P0070-1C. WWH-OBD streamlines OBD2 car diagnostics by providing more specific fault details.
WWH also offers more fault information, such as severity/class and status. Severity will indicate how quickly the fault needs to be reviewed, while the fault class will indicate which group the fault belongs to 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. This detailed fault information significantly improves OBD2 car diagnostics accuracy and efficiency.
In summary, WWH-OBD expands on the current OBDII framework to offer even more diagnostic information to the user, advancing the field of OBD2 car diagnostics.
Geotab Supports 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). Geotab’s support for WWH-OBD ensures future-proof OBD2 car diagnostics capabilities.
At Geotab, we are constantly improving our firmware to further expand the information our customers receive. We have already started supporting 3-byte DTC information and continue to add more fault information being 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 cloud so our customers always get the most benefit from their devices, ensuring they have access to the latest advancements in OBD2 car diagnostics.
Growth Beyond OBDII
OBDII contains 10 standard modes to get the diagnostic information required by emissions standards. The problem is these 10 modes have not been sufficient. The evolution of OBD2 car diagnostics necessitates going beyond the limitations of the original OBDII standards.
Over the years since the implementation of OBDII, several UDS modes have been developed to enrich the available data. Each vehicle manufacturer uses their own PIDs and implements them using additional UDS modes. Information that was not required through OBDII data (such as odometer and seat belt usage) became available through UDS modes. UDS modes extend the reach of OBD2 car diagnostics by providing access to more vehicle data.
The reality is that UDS contains more than 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, which seeks to incorporate UDS modes with OBDII to enrich the data available for diagnostics, while still maintaining a standardized process. WWH-OBD aims to standardize and enhance OBD2 car diagnostics by integrating UDS capabilities.
Conclusion
In the growing world of IoT, the OBD port remains important for vehicle health, safety, and sustainability. Although the number and variety of connected devices for vehicles is increasing, not all devices give and track the same information. In addition, compatibility and security can vary from device to device. The standardization and evolution of OBD2 car diagnostics are crucial for the future of connected vehicles.
With the multitude of OBD protocols, not all telematics solutions are designed to work with every type of vehicle currently available. Good telematics solutions should be able to understand and translate a comprehensive set of vehicle diagnostic codes. Choosing a robust telematics solution is key to leveraging the full potential of OBD2 car diagnostics for vehicle management and maintenance.
