GM Service Manual Online
For 1990-2009 cars only
    • If there is a strong magnetic field in the area near the mirror, the compass circuit cannot compensate for the magnetic field.
    • Inspect for the following possible magnetic fields:
        1. Magnetic antenna mount
        2. Magnetic notepad holder
        3. Any similar magnetized items in the area of the mirror
    • In order to fix a problem with a strong magnetic field, perform the following steps:
        1. Remove the magnetic item.
        2. Turn the mirror OFF for 30 seconds.
        3. Turn the mirror back ON.
        4. If the mirror comes back on displaying direction or a C, inform vehicle owner of offending magnetic part. Refer to Compass Calibration Description .
        5. If the mirror still displays all segments, replace the mirror assembly.