Understanding Auxiliary Vehicle ID Reset: A Comprehensive Guide
In today’s high-tech automotive world, vehicles are equipped with a wide array of electronic systems and components that work together to provide safety, performance, convenience and diagnostic capabilities. One important but often overlooked aspect is the auxiliary vehicle identification (ID) system. This system plays a crucial role in uniquely identifying a vehicle and its specific configuration. In certain situations, such as after replacing electronic control modules, it may be necessary to perform an auxiliary vehicle ID reset procedure.
In this comprehensive guide, we’ll take an in-depth look at what the auxiliary vehicle ID system is, how it works, when an ID reset is required, and the step-by-step process to carry out this important task. Whether you’re a professional mechanic, a DIY enthusiast, or simply curious about the inner workings of modern vehicles, this post will provide valuable insights.
What is an Auxiliary Vehicle ID?
An auxiliary vehicle ID is a unique digital identification assigned to a vehicle by the manufacturer. It contains key information about the specific make, model, year, installed equipment and other details about how the vehicle is configured. This ID enables various control modules in the vehicle to recognize that they are installed in a particular car and to function together properly as an integrated system.
The auxiliary ID is typically stored in each compatible control module’s memory. Modules that commonly use the auxiliary ID include:
- Powertrain Control Module (PCM)
- Transmission Control Module (TCM)
- Anti-lock Brake System (ABS) Module
- Airbag Control Module (ACM)
- Body Control Module (BCM)
When these modules communicate with each other through the vehicle’s controller area network (CAN) bus, they use the shared auxiliary ID to verify they are all installed in the same vehicle. This ensures the modules are compatible and their software is properly configured for that specific vehicle….
The auxiliary ID is programmed into the modules when the vehicle is manufactured and is also stored in a central database by the automaker, tied to the vehicle identification number (VIN). This allows replacement modules to be programmed with the correct ID by a dealership or qualified repair shop.
When is an Auxiliary Vehicle ID Reset Needed?
In most cases, a vehicle’s auxiliary ID system will continue functioning properly for the life of the vehicle without needing any special attention. However, certain repair or modification scenarios will require resetting and/or reprogramming the ID in one or more modules:
Replacing a Control Module
If a control module such as the PCM, TCM, ABS, ACM or BCM is replaced due to failure or damage, the new module will need to be programmed with the vehicle’s auxiliary ID. Until this is done, the module will not be recognized by the other modules and systems in the vehicle, likely resulting in drivability issues, fault codes and warning lights.
The replacement module may be a brand new unit or one that was previously installed in a different vehicle. In either case, it will initially have a generic or different ID that will not match the vehicle’s ID.
Swapping Modules Between Vehicles
Some vehicle enthusiasts may swap control modules between two vehicles to upgrade performance or enable certain features. For example, installing the PCM from a higher horsepower model of the same vehicle make. In this case, the auxiliary ID of the swapped module will not match the ID in the other control modules in the vehicle. The ID will need to be reset or reprogrammed to the vehicle’s original ID for all systems to work harmoniously together.
Updating Module Software
Automakers occasionally release software updates for various control modules to fix bugs, improve performance or add new features. When the module software is updated by a dealership or repair shop, the auxiliary ID is sometimes overwritten in the process. After a software update, some automakers require performing an auxiliary ID reset to restore the original ID and ensure all modules are back in sync.
The Auxiliary ID Reset Process…
The exact steps to reset a vehicle’s auxiliary ID will vary between makes and models. However, the general process typically involves these key phases:
- Identify Affected Modules – First, the technician needs to determine which control modules are affected by the repair or modification that necessitates the ID reset. This is done by connecting a diagnostic scan tool to the vehicle’s data link connector (DLC) and reading fault codes. Modules that have lost their auxiliary ID or have a mismatched ID will usually store a specific diagnostic trouble code (DTC) indicating an “invalid ID” or “ID mismatch”. The scan tool can also be used to check each module’s programmed ID compared to the expected original ID.
- Connect to Manufacturer’s Database – With the affected modules identified, the technician needs to connect the scan tool to the automaker’s database to look up the correct auxiliary ID for the vehicle. This is done by providing the vehicle’s VIN and following the prompts in the scan tool’s software. The database will return the original ID that was assigned to the vehicle when it was manufactured. This is the ID that needs to be programmed back into the affected modules.
- Program the Correct ID – With the correct ID obtained, the technician can now use the scan tool to program it into each affected module. The exact menu selections and commands to do this vary by scan tool and vehicle make. In general, the technician will select the module to be programmed, enter the ID, and the scan tool will overwrite the module’s stored ID with the new one. Some automakers refer to this as an “ID relearn” while others call it “ID synchronization.”
- Verify the ID Reset – After all affected modules are programmed, the technician should use the scan tool to recheck each module and verify it now has the correct ID stored in memory. The “invalid ID” or “ID mismatch” DTCs should be cleared. Finally, a short test drive is usually recommended to verify the vehicle runs properly and all systems are communicating correctly with the matching ID.
Real-World Auxiliary ID Reset Examples…
To illustrate the auxiliary ID reset process, let’s look at a couple specific examples on popular vehicle makes.
Ford Auxiliary ID Reset
On many Ford vehicles, the auxiliary ID reset is referred to as “Parameter ID (PID) Fusion” in the service literature. If the PCM is replaced, the PID Fusion must be performed to program the new PCM with the vehicle’s original auxiliary ID.
The PID Fusion process is carried out using the Ford IDS scan tool and involves these steps:
- Connect the IDS to the vehicle’s DLC
- Retrieve the vehicle’s VIN from the IDS
- Select the “Module Programming” menu
- Select “PCM” from the list of modules
- Select “PID Fusion”
- Follow the on-screen instructions to complete the programming
- Verify the PCM now has the correct PID programmed
GM Auxiliary ID Reset
General Motors refers to the auxiliary ID as the “Vehicle ID” or “VIN ID” in their service information. If multiple control modules are replaced, the Vehicle ID must be reset in each module to restore communication.
The Vehicle ID reset on most GM vehicles involves:
- Connect a compatible scan tool (Tech2, MDI, GDS2, etc.)
- Select “Vehicle ID Reset” from the programming menu
- Select all the replaced control modules from the list
- Command the scan tool to reset the ID in the selected modules
- Follow any additional on-screen instructions
- Verify all modules now have the correct Vehicle ID
The Importance of Proper ID Reset
Performing an auxiliary ID reset when needed is crucial for restoring proper communication and functionality between a vehicle’s control modules after a repair or module replacement. Neglecting this important step can result in:
- Modules not communicating
- Drivability issues (poor performance, rough running, stalling)
- Fault codes and warning lights
- Certain features not working properly
- Reduced fuel efficiency
- Increased emissions
In extreme cases, failure to reset the ID could even result in modules remaining in “factory mode” which may disable key safety systems like anti-lock brakes and airbags. For these reasons,… the auxiliary ID reset should always be performed by a qualified professional using the proper tools and procedures.
Key Takeaways
- The auxiliary vehicle ID is a unique digital identifier assigned to a vehicle during manufacturing and stored in each compatible control module
- The ID allows modules to recognize each other and function together properly as a system
- Common reasons for an auxiliary ID reset include: replacing a control module, swapping modules between vehicles, and updating module software
- The reset procedure involves identifying affected modules, looking up the original ID, programming the ID into the modules, and verifying the reset
- Resetting the auxiliary ID when required is critical for proper communication, drivability, safety and emissions
- Understanding the auxiliary ID system is valuable knowledge for technicians and vehicle owners alike…
Conclusion
The auxiliary vehicle identification system is a behind-the-scenes but vitally important aspect of how modern vehicles function. This unique digital ID allows the various electronic control modules in a vehicle to all work together as a cohesive system.
Whenever major repairs or module replacements are performed, resetting and/or reprogramming the auxiliary ID is a necessary final step to restore proper communication between modules. Knowing when an ID reset is needed and how to properly carry out the procedure is essential for today’s automotive technicians.
For vehicle owners, understanding the auxiliary ID system provides helpful background knowledge when faced with repairs or issues involving the vehicle’s control modules and electronic systems. If a repair shop recommends an auxiliary ID reset or reprogramming, this guide will help clarify what that means and why it’s important.
As vehicles continue to grow more computerized and interconnected, the auxiliary ID system and reset procedures will only become more crucial in the years ahead. Mastering these concepts and processes will be key for technicians to effectively service and repair the vehicles of tomorrow.