CTS RWD V6-3.6L (2008)
Accessory Control Display: Customer Interest
Instruments - Display Locked Up/Compass Error
TECHNICAL
Bulletin No.: 08-08-49-008A
Date: May 14, 2008
Subject:
Compass Error or Display Locked‐Up After Remote Start in Cold Temperatures (Reprogram HVAC Module)
Models:
2008 Cadillac CTS
with Remote Start (RPO, UHA, UHB or UHC)
Supercede:
This bulletin is being revised to change the labor operation number in the Warranty Information section. Please discard Corporate Bulletin Number
08-08-49-008 (Section 08 - Body and Accessories).
Condition
Some customers may comment that the compass feature in the driver information center (DIC) reads incorrectly or is locked‐up after the vehicle
is remote started in cold temperatures (approximately less than 9°C (48°F)).
Cause
The electronic compass module may not recalibrate properly after remote start due to electrical magnetic influence of the rear window defroster. The rear
window defroster operation is controller by the HVAC control module.
Correction
A revised HVAC operating system calibration has been released to address this condition. This new service calibration will cancel automatic rear
defroster operation after transitioning from remote start to run in cold temperatures allowing the compass module to recalibrate correctly. Reprogram the
HVAC module with updated calibration files using the TIS2WEB Service Programming System (SPS) application. There are 2 calibrations part numbers
that are valid for "Operating System". Read the descriptions to determine the correct calibration for the vehicle. After completing the software update,
recalibrate the compass using published procedures.
Rear window defroster operation during remote start will not be affected by this change.
Important:
Compass calibration error could still occur if the rear window defroster is manually selected by the customer very quickly (less than two seconds)
after normal starting or remote start transition to run. Please advise the customer to allow a few seconds before engaging the rear window defroster to
ensure proper operation of the compass.
Warranty Information
For vehicles repaired under warranty, use the table.
Disclaimer
