Experiencing a “No Fob Detected” message in your C6 Corvette can be frustrating. Imagine being ready to drive, only to be greeted by this alert on your Driver Information Center (DIC). This issue, common in C6 Corvettes, prevents your car from recognizing your key fob, essentially leaving you stranded even with the fob in your pocket. Let’s delve into why this happens and how to address it.
Decoding the “No Fob Detected” Message on Your C6 Corvette
When your C6 Corvette flashes the “No Fob Detected” message, it signifies a communication breakdown between your key fob and the vehicle’s Remote Control Door Lock Receiver (RCDLR) module. Alongside this DIC message, you might also encounter a scenario where your Corvette honks three times when you exit the vehicle – a “key in reminder” even when you’ve taken the fob with you. These symptoms often point to the same underlying problem related to how your Corvette senses the key fob’s presence.
The Root Cause: RCDLR Software and Detection Zones
For C6 Corvettes manufactured before October 2007, the culprit often lies within the RCDLR software. The original software in these models had limitations in its detection zones, particularly around the driver’s seat area. This means that if your key fob was placed on the driver’s seat or was just outside the driver’s door, the system might fail to recognize it. This deficiency in the early RCDLR software is the reason behind the “No Fob Detected” message and the erroneous key reminder chimes.
General Motors addressed this issue with a service bulletin, PIC4642A, which specifically targets 2005-2008 Chevrolet Corvettes and Cadillac XLR models experiencing these symptoms. The bulletin highlights that the original RCDLR software needed improvement in covering the driver’s seat area and preventing false detections when the fob was just outside the car.
The Software Update Solution: Reprogramming Your RCDLR
The recommended fix, as outlined in the service bulletin, is to reprogram the RCDLR with updated software. This update introduces a new detection zone that better encompasses the driver’s seat. It also incorporates a brief two-second delay after the door closes before the system checks for the fob inside the vehicle. These enhancements significantly reduce the chances of encountering the “No Fob Detected” message and the key-in-reminder honks.
Important Note: Performing the RCDLR reprogramming typically requires specialized equipment and access to GM’s TIS2WEB service. It’s a procedure best left to qualified technicians at a Chevrolet dealership or a trusted automotive repair shop experienced with Corvette electronics.
Key Steps in the RCDLR Reprogramming Process (For Technician Reference):
- Fuse Removal: Before programming, it’s crucial to remove the radio and HVAC fuses located in the BCM fuse block (passenger floor electrical center). Specifically, the fuses labeled “RDO/S’BAND/VICS” and “HVAC/PWR SND” need to be removed. The ignition should be in the “Key On Engine Off Mode”.
- Programming: Using TIS-2-WEB “Pass Through” method, program the RCDLR with the revised software. Select “Replace and Reprogram ECU” during the programming process.
- Potential “Locked Up” State Recovery: In rare cases, the RCDLR might enter a “locked up” state during programming. If this happens, do not turn off the ignition. Reset the RCDLR by removing fuse #11 in the UBEC (underhood electrical center) for at least 30 seconds. Reinstall the fuse and restart the programming within a 2-minute window using TIS2WEB.
- Software Versions:
- For 2005-2007 models, use software version 25927325.
- For 2008 models, use software version 25927326.
Crucially, the service bulletin emphasizes: DO NOT REPLACE THE RCDLR MODULE – REPROGRAMMING IS THE SOLUTION. Also, key fob programming and TPM (Tire Pressure Monitoring) learn procedures are not required after the RCDLR reprogramming.
Other Potential Causes of “Key Fob Not Detected”
While the RCDLR software update addresses a common cause, other factors can also lead to a “Key Fob Not Detected” message:
- Low Key Fob Battery: A weak battery in your key fob is a frequent culprit. Try replacing the battery with a fresh one.
- Key Fob Malfunction: Less commonly, the key fob itself might be faulty. If you have a spare fob, test if it works. If neither fob is detected, the issue is likely with the car.
- Vehicle Battery Issues: While less directly related to fob detection, a low car battery or issues with the car’s electrical system could potentially interfere with the RCDLR’s operation.
Conclusion: Resolving Your C6 Corvette Key Fob Detection Issues
If you’re consistently seeing the “No Fob Detected” message in your 2005-2008 C6 Corvette, especially if accompanied by the key-in-reminder honks, the RCDLR software update is the most probable solution. Consult with a qualified technician to have your RCDLR reprogrammed. If the problem persists after the update, or if your Corvette is a later model, investigate other potential causes like a low fob battery or key fob malfunction. Addressing this issue will restore the convenience and reliability of your Corvette’s keyless entry system.
