What’s the Difference Between OBD2 vs OBD3?

OBD2 and OBD3 represent different stages in the evolution of vehicle diagnostic systems. OBD2 is the current standard, while OBD3 is a proposed future system. OBD2 enables mechanics to diagnose car issues, while OBD3 aims to automate this process through telematics. Discover how these systems work and what the future holds at OBD2-SCANNER.EDU.VN, your go-to resource for vehicle diagnostics and repair solutions. Explore the advancements in automotive technology, including diagnostic tools and remote monitoring, by reading on and learning more about scan tools, error codes, and car diagnostics.

1. What is OBD2?

OBD2, or On-Board Diagnostics II, is a vehicle’s self-diagnostic system, standardized to extract diagnostic trouble codes (DTCs) and real-time data via the OBD2 connector. This system helps in identifying issues through a malfunction indicator light on the dashboard and allows mechanics to use OBD2 scanners for faster troubleshooting. OBD2 improves vehicle maintenance by providing quick access to critical car information.

2. Understanding the History of OBD2

OBD2’s history began in California, driven by the California Air Resources Board (CARB), which mandated OBD in all new cars from 1991 for emission control. The Society of Automotive Engineers (SAE) further standardized DTCs and the OBD connector (SAE J1962). The rollout of OBD2 happened gradually:

• 1996: Mandatory in the USA for cars and light trucks.
• 2001: Required in the EU for gasoline cars.
• 2003: Required in the EU for diesel cars (EOBD).
• 2005: Required in the US for medium-duty vehicles.
• 2008: US cars mandated to use ISO 15765-4 (CAN) as the OBD2 foundation.
• 2010: Required in US heavy-duty vehicles.

3. Is OBD2 Compatibility Guaranteed in My Car?

Most likely, yes. Almost all newer non-electric cars support OBD2, mainly running on the CAN bus. For older models, compliance can be determined by checking where and when the car was bought. The OBD2 standard ensures that vehicles meet specific diagnostic requirements, which helps car owners and mechanics to easily access vehicle data.

4. Exploring the Future Trends: What is OBD3?

OBD3 represents the next leap in vehicle diagnostics by incorporating telematics into all cars. OBD3 adds a radio transponder to vehicles, enabling them to send vehicle identification numbers (VIN) and DTCs via WiFi to a central server for automatic checks. This advancement allows for real-time monitoring and remote diagnostics, which could revolutionize how vehicle maintenance and emissions are managed.

Many devices today facilitate the transfer of CAN or OBD2 data via WiFi/cellular, such as the CANedge2 WiFi CAN logger or the CANedge3 3G/4G CAN logger.

5. Decoding OBD2 Standards and Protocols

OBD2 operates as a higher-layer protocol, similar to a language, while CAN functions as a communication method, like a phone. This setup allows OBD2 to work with other CAN-based protocols such as J1939, CANopen, and NMEA 2000. The standards outline the OBD2 connector, lower-layer protocols, and OBD2 parameter IDs (PID), among other elements.

6. Overview of the OBD2 Connector [SAE J1962]

The 16-pin OBD2 connector provides easy access to your car’s data, as specified in SAE J1962 / ISO 15031-3. Key points include:

• The connector is usually near the steering wheel.
• Pin 16 provides battery power.
• The OBD2 pinout varies depending on the communication protocol.
• CAN bus is the most common lower-layer protocol, typically connecting pins 6 (CAN-H) and 14 (CAN-L).

7. Decoding OBD2 Connector Types: A vs. B

You may find both type A and type B OBD2 connectors. Type A is standard in cars, while type B is common in medium and heavy-duty vehicles. They share similar pinouts but differ in power supply outputs (12V for type A and 24V for type B). A type B OBD2 adapter cable is compatible with both types, while a type A will not fit into a type B socket.

8. Unpacking OBD2 and CAN Bus [ISO 15765-4]

Since 2008, CAN bus has been mandatory for OBD2 in US cars, as per ISO 15765. ISO 15765-4 (Diagnostics over CAN or DoCAN) standardizes the CAN interface for test equipment, focusing on the physical, data link, and network layers. Key specifications include:

• CAN bus bit-rate of 250K or 500K.
• CAN IDs can be 11-bit or 29-bit.
• Specific CAN IDs are used for OBD requests/responses.
• Diagnostic CAN frame data length of 8 bytes.
• OBD2 adapter cable length up to 5 meters.

9. Identifying OBD2 CAN Identifiers (11-bit, 29-bit)

OBD2 communication involves request/response messages. Most cars use 11-bit CAN IDs, with the ‘Functional Addressing’ ID being 0x7DF. ECUs respond with 11-bit IDs 0x7E8-0x7EF. Some vehicles use extended 29-bit CAN identifiers, with a ‘Functional Addressing’ CAN ID of 0x18DB33F1.

10. OBD2 vs. Proprietary CAN Protocols: What’s the Difference?

Your car’s ECUs don’t rely on OBD2 to function. Each OEM implements their proprietary CAN protocols, specific to the vehicle brand, model, and year. If you connect a CAN bus data logger to your car’s OBD2 connector, you may see the OEM-specific CAN data, typically broadcast at a rate of 1000-2000 frames/second. However, many newer cars use a ‘gateway’ to block access to this CAN data, only enabling OBD2 communication via the OBD2 connector. OBD2 is like an ‘extra’ higher-layer protocol in parallel to the OEM-specific protocol.

11. Mastering Bit-Rate and ID Validation

OBD2 may use bit-rates of 250K or 500K and CAN ID lengths of 11-bit or 29-bit. ISO 15765-4 provides recommendations for a systematic initialization sequence to determine the correct combination. Test tools may send UDS requests to determine the protocol of OBDonEDS vs OBDonUDS. OBDonEDS (aka OBD2, SAE OBD, EOBD, or ISO OBD) is mainly used in non-EV cars, while WWH-OBD is used in EU trucks/buses.

12. Identifying The Five Lower-Layer OBD2 Protocols

While CAN is the primary lower-layer protocol for OBD2 today, older cars may use other protocols. Understanding these can help in diagnosing older vehicle systems:

• ISO 15765 (CAN bus): Predominantly used in most cars since 2008.
• ISO14230-4 (KWP2000): Common in 2003+ cars, especially in Asia.
• ISO 9141-2: Used in EU, Chrysler & Asian cars in 2000-04.
• SAE J1850 (VPW): Mostly used in older GM cars.
• SAE J1850 (PWM): Primarily used in older Ford cars.

13. How is OBD2 Data Transported Via ISO-TP [ISO 15765-2]?

All OBD2 data is communicated on the CAN bus through ISO-TP (ISO 15765-2), a transport protocol enabling payloads larger than 8 bytes. This is used in OBD2 to extract the Vehicle Identification Number (VIN) or Diagnostic Trouble Codes (DTCs). ISO 15765-2 supports segmentation, flow control, and reassembly.

14. Breaking Down the OBD2 Diagnostic Message [SAE J1979, ISO 15031-5]

An OBD2 message includes an identifier, data length (PCI field), and data, split into Mode, parameter ID (PID), and data bytes. Understanding this structure is crucial for interpreting vehicle diagnostics.

15. Requesting and Responding: An OBD2 Example

For example, to request the parameter ‘Vehicle Speed’, an external tool sends a message to the car with CAN ID 0x7DF and two payload bytes: Mode 0x01 and PID 0x0D. The car responds via CAN ID 0x7E8 with three payload bytes, including the vehicle speed value. By knowing the decoding rules for PID 0x0D, you can determine the vehicle’s speed.

16. Demystifying the 10 OBD2 Services (aka Modes)

There are 10 OBD2 diagnostic services or modes. Mode 0x01 displays current real-time data, while others are used to show/clear diagnostic trouble codes (DTCs) or show freeze frame data. Vehicles don’t have to support all OBD2 modes and may support OEM-specific modes. In OBD2 messages, the mode is in the 2nd byte, with 0x40 added to the mode in the response.

17. Delving into OBD2 Parameter IDs (PIDs)

Each OBD2 mode contains parameter IDs (PIDs). For example, mode 0x01 contains ~200 standardized PIDs with real-time data such as speed, RPM, and fuel level. However, vehicles don’t have to support all PIDs in a mode. If an emissions-related ECU supports any OBD2 services, it must support mode 0x01 PID 0x00, which helps determine support for PIDs 0x01-0x20.

18. Utilizing the OBD2 PID Overview Tool

Use the OBD2 PID overview tool to find scaling information for standard OBD2 PIDs, which helps you decode data into physical values. This tool assists in constructing OBD2 request frames and dynamically decoding OBD2 responses.

19. Step-by-Step: Logging and Decoding OBD2 Data

You can log OBD2 data using tools like the CANedge CAN bus data logger. Configure the CANedge to transmit custom CAN frames and connect it to your vehicle via an OBD2-DB9 adapter cable.

20. Performing Key Steps: Testing Bit-Rate, IDs, and Supported PIDs

ISO 15765-4 describes how to determine the bit-rate and IDs used by a vehicle. Here’s how to test with CANedge:

1. Send a CAN frame at 500K and check if successful.
2. Use the identified bit-rate for communication.
3. Send multiple ‘Supported PIDs’ requests.
4. Determine 11-bit vs. 29-bit based on response IDs.
5. See supported PIDs based on response data.

Most 2008+ non-EV cars support 40-80 PIDs via a 500K bit-rate, 11-bit CAN IDs, and the OBD2/OBDonEDS protocol.

21. Configuring OBD2 PID Requests: A Practical Guide

After determining the supported PIDs, configure your transmit list. Consider these points:

• CAN IDs: Use ‘Physical Addressing’ request IDs (e.g., 0x7E0).
• Spacing: Add 300-500 ms between requests.
• Battery drain: Use triggers to stop transmitting when inactive.
• Filters: Add filters to record only OBD2 responses.

22. Decoding Raw OBD2 Data with DBC: A How-To Guide

To analyze your data, decode the raw OBD2 data into physical values. Use the OBD2 DBC file to DBC decode the data in CAN bus software tools. Since different OBD2 PIDs are transported using the same CAN ID, leverage both the CAN ID, OBD2 mode, and OBD2 PID to identify the signal.

OBD2 data decoded visual plot asammdf CAN bus DBC file

23. Understanding OBD2 Multi-Frame Examples [ISO-TP]

OBD2 data is communicated using ISO-TP (ISO 15765-2). Multi-frame communication requires flow control frames. Use CAN software/API tools that support ISO-TP, like the CANedge MF4 decoders.

OBD2-multi-frame-request-message-vehicle-identification-number

24. Extracting the Vehicle Identification Number (VIN) with OBD2

To extract the VIN from a vehicle using OBD2, use mode 0x09 and PID 0x02. The tester tool sends a Single Frame request, and the vehicle responds with a First Frame containing the PCI, length, mode, and PID.

25. Demystifying OBD2: Multi-PID Requests (6x)

External tools can request up to 6 mode 0x01 OBD2 PIDs in a single request frame. The ECU responds with data for supported PIDs across multiple frames. This method lets you collect OBD2 data at a higher frequency, though the signal encoding is specific to your request method.

26. Obtaining Diagnostic Trouble Codes (DTCs) Using OBD2

Request emissions-related DTCs using mode 0x03. The ECU responds with the number of DTCs stored, with each DTC taking up 2 data bytes. The 2-byte DTC value is split into a category and a 4-digit code.

27. OBD2 Data Logging: Real-World Use Case Examples

OBD2 data can reduce fuel costs, improve driving, test prototype parts, and aid insurance assessments. IoT OBD2 loggers can monitor vehicles to predict and avoid breakdowns. An OBD2 logger can act as a ‘blackbox’ for vehicles, providing data for disputes or diagnostics.

28. Why Are Electric Vehicles and OBD2 a Complicated Relationship?

Electric vehicles (EVs) typically do not support standard OBD2 protocols due to their different emission and diagnostic needs compared to internal combustion engine vehicles. While OBD2 was designed for emission controls, which are less relevant for EVs, these vehicles often use OEM-specific UDS communication protocols, making it difficult to decode data without specific knowledge or reverse engineering.

29. What are the Key Differences in Data Access Between OBD2 and Newer Systems Like WWH-OBD?

OBD2, traditionally focused on emission diagnostics, uses a set of standardized PIDs that are publicly documented, allowing for broad compatibility across different scan tools. Newer systems like WWH-OBD (World Wide Harmonized OBD) streamline and enhance OBD communication using the UDS protocol. Unlike OBD2, WWH-OBD and other UDS-based systems offer more flexibility in data parameters, but may require more specialized equipment and knowledge to access and interpret the data.

30. How Does OBD2 Compare to OEM-Specific Diagnostic Tools in Terms of Functionality?

OBD2 provides a basic level of diagnostic information that is standardized across vehicles to meet regulatory requirements. OEM-specific diagnostic tools, on the other hand, offer deeper access to vehicle systems and more detailed diagnostics, including functionalities like reprogramming ECUs, running advanced diagnostics tests, and accessing proprietary data. While OBD2 tools are versatile and can be used on a wide range of vehicles, OEM tools provide functionalities that are tailored to specific makes and models, offering a more comprehensive diagnostic solution.

31. What Challenges Do Mechanics Face When Working with Both OBD2 and Proprietary Systems?

Mechanics face several challenges when working with both OBD2 and proprietary systems:

• Tool Investment: Requires investment in both OBD2 scanners for basic diagnostics and potentially expensive OEM-specific tools for advanced diagnostics.
• Training: Needs to stay updated with the latest technologies and protocols for both systems, requiring ongoing training and certifications.
• Data Interpretation: Must be able to interpret both standardized OBD2 codes and OEM-specific data, which may require access to detailed service manuals and databases.
• Compatibility Issues: Encountering compatibility issues between aftermarket tools and specific vehicle models can hinder diagnostic efforts.
• Security Concerns: Addressing security issues when accessing and modifying vehicle systems, especially with the increasing risk of cyber threats.

32. What are the Key Limitations of the OBD2 Protocol that OBD3 Aims to Overcome?

OBD2 has several limitations that OBD3 aims to address, including:

• Limited Data: OBD2 provides a limited set of standardized data parameters, which may not be sufficient for diagnosing complex issues.
• Lack of Real-Time Monitoring: OBD2 requires manual intervention for data retrieval, lacking real-time monitoring capabilities.
• Inconsistent Implementation: Variations in implementation across different manufacturers can lead to inconsistent diagnostic results.
• Security Vulnerabilities: OBD2 is susceptible to security vulnerabilities, making it a potential entry point for vehicle hacking.
• Scalability Issues: OBD2 lacks the scalability needed to support the increasing complexity of modern vehicle systems.

OBD3 aims to overcome these limitations by incorporating telematics for real-time monitoring, expanding data parameters, improving security, and standardizing implementation across manufacturers.

33. What Security Measures Are Planned for OBD3 to Prevent Unauthorized Access and Vehicle Hacking?

OBD3 incorporates several security measures to prevent unauthorized access and vehicle hacking, including:

• Encryption: Encrypting all data transmitted wirelessly to prevent eavesdropping and tampering.
• Authentication: Implementing strong authentication protocols to verify the identity of authorized users and devices.
• Firewalls: Using firewalls to restrict access to sensitive vehicle systems and prevent unauthorized modifications.
• Intrusion Detection: Monitoring vehicle networks for suspicious activity and automatically blocking potential intrusions.
• Over-the-Air Updates: Providing regular security updates to address vulnerabilities and improve system resilience.

These measures help ensure that OBD3 systems are secure and protect against cyber threats.

34. How Will OBD3 Affect the Automotive Repair Industry?

OBD3 has the potential to significantly affect the automotive repair industry by:

• Enhancing Diagnostic Accuracy: Real-time data and remote diagnostics can improve the accuracy and speed of diagnosing vehicle issues.
• Facilitating Predictive Maintenance: Monitoring vehicle health can enable predictive maintenance, reducing breakdowns and repair costs.
• Improving Customer Service: Remote diagnostics can allow repair shops to offer proactive customer service and address issues before they escalate.
• Increasing Efficiency: Automation of diagnostic processes can increase efficiency and reduce the time needed for repairs.
• Creating New Business Models: New business models may emerge, such as remote diagnostic services and subscription-based maintenance plans.

While OBD3 offers many benefits, it may also pose challenges for repair shops that are not equipped to handle the new technology.

35. How Does the Automotive Industry View the Potential Shift From OBD2 to OBD3?

The automotive industry has mixed views on the potential shift from OBD2 to OBD3:

• OEMs: Automakers may support OBD3 for its potential to improve vehicle maintenance and customer service, but may also be concerned about security and data privacy issues.
• Suppliers: Technology suppliers see OBD3 as an opportunity to develop new products and services, such as telematics solutions and diagnostic tools.
• Repair Shops: Independent repair shops may be hesitant about OBD3 due to the potential costs of adopting new technology and the risk of being locked out of vehicle diagnostics.
• Consumers: Car owners may appreciate the convenience of remote diagnostics and predictive maintenance, but may also be concerned about privacy and data security.

Overall, the shift from OBD2 to OBD3 will require collaboration and consensus among all stakeholders in the automotive industry.

36. What are the Broader Implications of Remote Vehicle Diagnostics for Data Privacy and Security?

Remote vehicle diagnostics raise several concerns about data privacy and security, including:

• Data Collection: Remote diagnostics systems collect vast amounts of data about vehicle usage, driver behavior, and vehicle health, which could be used for purposes other than diagnostics.
• Data Storage: Sensitive vehicle data is stored in the cloud, making it vulnerable to data breaches and unauthorized access.
• Data Sharing: Vehicle data may be shared with third parties, such as insurance companies, advertisers, and government agencies, without the owner’s consent.
• Cybersecurity Risks: Remote diagnostics systems are vulnerable to cyberattacks, which could allow hackers to take control of vehicle systems or steal sensitive data.
• Privacy Regulations: Existing privacy regulations may not be adequate to protect vehicle data, and new regulations may be needed to address these concerns.

37. How Does Remote Vehicle Diagnostics Impact Vehicle Owners?

Remote vehicle diagnostics offers several potential benefits to vehicle owners:

• Improved Vehicle Maintenance: Real-time monitoring and predictive maintenance can help prevent breakdowns and reduce repair costs.
• Faster and More Accurate Diagnostics: Remote diagnostics can enable repair shops to diagnose issues more quickly and accurately, reducing downtime.
• Proactive Customer Service: Repair shops can offer proactive customer service and address issues before they escalate.
• Enhanced Safety: Remote diagnostics can detect safety-related issues and alert drivers to potential hazards.
• Convenience: Vehicle owners can monitor their vehicle’s health remotely, without having to visit a repair shop.

However, remote vehicle diagnostics also raises concerns about privacy and data security, which need to be addressed to ensure that vehicle owners are protected.

At OBD2-SCANNER.EDU.VN, we understand the challenges you face in diagnosing and repairing modern vehicles. That’s why we’re here to help. Contact us today at 123 Main Street, Los Angeles, CA 90001, United States, or call us at +1 (641) 206-8880 for expert advice and solutions.