The 2008 Chevrolet Cobalt, like many modern vehicles, came equipped with a keyless entry system for enhanced convenience. However, owners may occasionally encounter issues with their key fobs becoming inoperative or the Tire Pressure Monitoring (TPM) system malfunctioning. This article delves into a specific service bulletin addressing these problems in the 2008 Chevy Cobalt, providing insights and potential solutions.
Understanding the Keyless Entry and TPM System Issues
According to a General Motors service bulletin #08-03-16-001B, some 2008 Chevrolet Cobalt, HHR, and Malibu, along with Pontiac G5, G6, Solstice, and Saturn AURA, SKY models, may experience problems with their keyless entry remotes and TPM systems. Customers might report that their key fobs are not working at all, or that the tire pressure display shows dashes for all four tires, indicating a failure in the TPM system readings.
Technicians investigating these issues may find Diagnostic Trouble Codes (DTCs) C0775, C0569, and B3105 stored in the Remote Control Door Lock Receiver (RCDLR) module. Furthermore, they might discover that the Tire Pressure Monitoring sensors cannot be programmed to the vehicle using the standard learn procedure of adding or releasing tire pressure while the vehicle is in TPM learn mode.
Root Causes of Key Fob and TPM Problems
The service bulletin identifies potential causes for these malfunctions. A primary reason could be a low voltage condition in the vehicle. If the vehicle experiences low voltage, the RCDLR module might lose its stored data related to the key fob transmitters and tire pressure monitoring.
Another contributing factor is a potential software issue within the RCDLR itself. The ability to initiate TPM learning by pressure changes could be disabled due to a software anomaly in the RCDLR module.
The Solution: RCDLR Reprogramming
To resolve these issues, the service bulletin recommends reprogramming the RCDLR module with updated software calibration. This updated software is designed to address both the key fob inoperability and the TPM system reading errors. The updated calibration is available through GM’s TIS2WEB service using the Service Programming System (SPS). It is crucial to ensure that the Tech 2® diagnostic tool being used for this procedure is updated with the latest software to guarantee successful communication and reprogramming.
Important Note for Technicians: In situations where the Tech 2® tool fails to establish communication with the RCDLR and the programming process ends with an error, the service bulletin provides a specific recovery procedure. Technicians should attempt to reprogram the RCDLR in SPS by selecting the option “Remote Control Door Lock Receiver (TSB 08-03-16-001) with E4399 error — Pass Thru Only.” This specialized procedure is designed to overcome communication issues and ensure successful reprogramming of the RCDLR.
Post-Reprogramming Procedures
Once the RCDLR module has been successfully reflashed with the updated software and calibrations, several additional steps might be necessary to fully restore the keyless entry and TPM system functionality. These steps include:
- Relearning all keyless entry transmitters (key fobs): After reprogramming, the RCDLR may need to be re-paired with all the vehicle’s key fobs. This procedure ensures that the system recognizes and responds to each remote.
- Reconfiguring the tire pressure placards and tire type: The software update might require resetting the tire pressure placard values and tire type information stored in the system.
- Relearning the tire pressure sensors: Similar to the key fobs, the TPM sensors in each wheel might need to be relearned by the RCDLR after the software update to ensure accurate tire pressure monitoring readings.
Detailed procedures for relearning transmitters, configuring placards and tire type, and relearning tire pressure sensors can be found in the Service Information (SI) system. Technicians should consult SI for the specific steps relevant to the 2008 Chevrolet Cobalt and other affected models.
Warranty and Labor Information
For warranty purposes, the service bulletin provides specific labor operation codes and times. The labor operation for reprogramming the Remote Control Door Lock Receiver (RCDLR) with SPS is R4481. The labor time for this operation is specified as “Use Published Labor Operation Time.” Additionally, an allowance of 0.0-0.3 hours of diagnosis time may be added as needed.
Conclusion
If you are experiencing issues with your 2008 Chevrolet Cobalt keyless entry remote or noticing dashes on your tire pressure readings, this service bulletin provides valuable information. While it is technically focused, it highlights a known software-related issue in the RCDLR module that can cause these problems. For owners encountering these symptoms, consulting a certified technician to diagnose and potentially reprogram the RCDLR is recommended. This action, based on the service bulletin’s guidance, can effectively restore the functionality of your keyless entry system and tire pressure monitoring.
