You might have come across the terms “OBD” or “OBD2” when exploring connected vehicles and devices like Geotab GO. These features are integral parts of modern car computer systems, with a history that’s richer than many realize. In this article, we’ll provide a comprehensive overview of OBD2, answering the key question: what is OBD2, and explore its evolution.
Understanding OBD: The Basics of On-Board Diagnostics
On-Board Diagnostics (OBD) refers to a vehicle’s self-diagnostic and reporting capability. It’s essentially the automotive electronic system that provides technicians and vehicle owners with access to the health information of various subsystems. An OBD system allows mechanics to tap into the car’s internal data to monitor performance and pinpoint repair needs efficiently.
OBD has become the standard protocol in most light-duty vehicles for retrieving diagnostic information. This data is generated by the Engine Control Units (ECUs), often referred to as the “brain” or computer of the vehicle. These ECUs constantly monitor and manage various aspects of the car’s operation.
Why is OBD2 So Important?
OBD2 plays a vital role in vehicle telematics and fleet management, offering invaluable insights into vehicle condition and driving behavior. Understanding what is OBD2 in practice reveals its significant benefits:
Thanks to OBD2, fleets and individual car owners can:
- Track Wear and Tear Trends: Identify which vehicle components are wearing out faster than expected, enabling preventative maintenance.
- Enable Proactive Vehicle Management: Instantly diagnose potential vehicle issues before they escalate, shifting from reactive repairs to proactive maintenance schedules.
- Measure Driving Behavior: Monitor speed, idling time, and other driving habits to improve efficiency and safety.
Locating the OBD2 Port in Your Vehicle
In most passenger vehicles, the OBD2 port is conveniently located on the underside of the dashboard, typically on the driver’s side. Depending on the vehicle type, the port may feature a 16-pin, 6-pin, or 9-pin configuration. The standardization to 16-pin is a key characteristic of OBD2, making it universally accessible.
OBD vs. OBD2: What’s the Difference?
Simply put, OBD2 is the second generation of OBD, or OBD I. The original OBD I systems were often external add-ons to a car’s console, while OBD2 is seamlessly integrated within the vehicle itself. OBD I was the standard until OBD2 was developed in the early 1990s, marking a significant leap in diagnostic capabilities and standardization. Understanding this evolution is crucial to grasping what is OBD2 and why it’s superior.
The Historical Journey of OBD2
The history of on-board diagnostics stretches back to the 1960s. Several pioneering organizations laid the groundwork for the standards we use 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, each manufacturer developed proprietary systems. This meant diagnostic tools were not universal; each manufacturer, and sometimes even different models from the same manufacturer, had unique connector types, electronic interface requirements, and custom trouble codes. This lack of uniformity highlighted the need for a common standard, which led to the development of OBD2.
Key Milestones in OBD History
1968 — Volkswagen introduces the first computer-based OBD system with scanning capabilities.
1978 — Datsun presents a simple OBD system, though with limited and 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 begins to take shape in the late 1980s following the SAE’s 1988 recommendation for a standard connector and diagnostic set.
1991 — The state of California mandates that all vehicles must have some form of basic on-board diagnostics, known as OBD I.
1994 — California mandates that all vehicles sold in the state from 1996 onwards must implement OBD as recommended by SAE, now termed OBD2, to facilitate widespread emissions testing. OBD2 included a set of standardized Diagnostic Trouble Codes (DTCs).
1996 — OBD-II becomes mandatory for all cars manufactured in the United States, marking a pivotal moment in automotive diagnostics.
2001 — EOBD (European version of OBD) becomes mandatory for all gasoline vehicles in the European Union.
2003 — EOBD extends to become mandatory for all diesel vehicles in the EU.
2008 — Starting in 2008, all vehicles in the United States are required to implement OBD2 via a Controller Area Network, as specified in ISO standard 15765-4, further enhancing data communication and standardization.
What Data Can You Access Through OBD2?
OBD2 provides access to a wealth of status information and Diagnostic Trouble Codes (DTCs) related to:
- Powertrain (Engine and Transmission): Monitoring engine performance, transmission health, and related systems.
- Emissions Control Systems: Ensuring vehicles comply with environmental regulations by tracking emissions-related components.
In addition to these, the following vehicle information is also accessible via OBD2:
- Vehicle Identification Number (VIN): Unique identifier of the vehicle.
- Calibration Identification Number: Software version identification for ECUs.
- Ignition Counter: Number of engine start cycles.
- Emissions Control System Counters: Data related to the performance of emission control components.
When you take your car to a service center, a mechanic connects a scan tool to the OBD port to read fault codes and identify issues. This capability allows for precise fault diagnosis, quicker vehicle inspections, and timely repairs before minor issues turn into major problems. This diagnostic efficiency is a core benefit of what is OBD2 offers.
Examples of OBD2 Data:
Mode 1 (Vehicle Information):
- Pid 12 — Engine RPM
- Pid 13 — Vehicle Speed
Mode 3 (Trouble 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
OBD2 and Telematics: A Powerful Combination
The presence of OBD2 empowers telematics devices to seamlessly process critical vehicle information such as engine RPM, vehicle speed, fault codes, fuel consumption, and much more. Understanding what is OBD2 in the context of telematics reveals its transformative impact on fleet management and vehicle tracking.
A telematics device can utilize 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, allowing fleet management teams to effectively monitor vehicle usage and performance.
Given the diverse range of OBD protocols, not all telematics solutions are designed to work universally across all vehicle types. Geotab telematics overcomes this challenge by intelligently translating diagnostic codes from various makes and models, including electric vehicles.
With the 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 OBD2 port, adapters can be used. In either case, the installation process remains rapid and doesn’t require specialized tools or professional installation assistance. This ease of integration underscores the practical advantages of what is OBD2 and its standardized approach.
What is WWH-OBD? Expanding Diagnostic Horizons
WWH-OBD stands for World Wide Harmonized On-Board Diagnostics. It represents an international standard for vehicle diagnostics, established 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, taking diagnostics to a more detailed level.
Advantages of WWH-OBD: A Technical Deep Dive
Transitioning to WWH-OBD offers several technical advantages:
Access to More Data Types
Current OBD2 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 OBD2 modes transitioning to WWH via Unified Diagnostic Services (UDS). Adopting WWH standards unlocks access to richer data and provides scalability for future data expansion.
More Granular Fault Data
Another key benefit of WWH-OBD is the enhanced detail in fault information. OBD2 currently uses a two-byte Diagnostic Trouble Code (DTC) to indicate a fault (e.g., P0070 for an ambient air temperature sensor “A” circuit malfunction).
Unified Diagnostic Services (UDS) expands the DTC from two to three bytes. The third byte signifies the “failure mode,” similar to the Failure Mode Indicator (FMI) in the J1939 protocol. For example, where OBD2 might list multiple codes for temperature sensor issues:
- 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
WWH-OBD consolidates these under a single code, P0070, with five different failure modes indicated in the third DTC byte. For instance, P0071 now becomes P0070-1C.
WWH-OBD also provides additional fault details like severity/class and status. Severity indicates the urgency of addressing the fault, while class categorizes the fault based on GTR specifications. Fault status indicates if the fault is pending, confirmed, or if testing is complete in the current driving cycle.
In summary, WWH-OBD significantly extends OBD2’s framework, delivering richer diagnostic insights. This advancement further clarifies what is OBD2 evolving into.
Geotab’s WWH-OBD Compatibility
Geotab has already integrated the WWH-OBD protocol into our firmware. Our system uses sophisticated protocol detection to securely identify the available protocols in a vehicle, determining if OBD2 or WWH-OBD (or sometimes both) are accessible.
At Geotab, we are committed to continuous firmware enhancements to maximize the information available to our clients. We’ve already begun supporting 3-byte DTC information and are continually adding more fault data from vehicles. When new information becomes available via OBD2 or WWH-OBD, or when new vehicle protocols are implemented, Geotab prioritizes rapid and accurate integration into our firmware. We then immediately deploy these firmware updates to our devices over the cloud, ensuring our customers always benefit from the most comprehensive data.
Expanding Beyond OBD2: The Growth of UDS
OBD2 includes 10 standard modes for accessing diagnostic information required for emissions standards. However, these modes have become insufficient for the increasing complexity of vehicle systems.
Since OBD2’s inception, various UDS modes have been developed to enrich available data. Vehicle manufacturers utilize proprietary PIDs implemented through additional UDS modes. Information not initially accessible via OBD2 data, such as odometer readings and seatbelt usage, became available through UDS modes.
UDS encompasses over 20 additional modes beyond the 10 standard OBD2 modes, offering a significantly broader data spectrum. WWH-OBD bridges this gap by incorporating UDS modes with OBD2, enhancing diagnostic data availability while maintaining a standardized framework. This progression highlights what is OBD2 becoming within the larger diagnostic landscape.
Conclusion: OBD2’s Enduring Relevance
In our increasingly connected world, the OBD port remains crucial for vehicle health, safety, and sustainability. While the number and variety of connected vehicle devices grow, not all devices provide or track the same information. Compatibility and security can also vary significantly.
Given the multitude of OBD protocols, not all telematics solutions are universally compatible. Effective telematics solutions must be capable of interpreting and translating a comprehensive range of vehicle diagnostic codes. Understanding what is OBD2 and its evolving standards is key to leveraging its full potential in vehicle management and beyond.
