Service VME - Rear View Mirror Compass Inaccurate or Out of Calibratiom - keywords accessory inoperative inside

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Some rear view mirrors equipped with a rear vision video screen (and a cost of $1,100.00) have been returned for compass related issues and only needed calibrating. Please do not replace any mirror assemblies without first thoroughly completing the "Compass Calibration and Magnetic Variance" procedure outlined in SI Document #763774.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.