Vehicle position icon constantly leaves road, moves erratically, or is displayed very far from actual vehicle position (while going through a tunnel) (With Display Audio (Without Navigation))

Diagnostic Procedure

Do the F-CAN and the B-CAN in the System Diagnostic Mode - Refer to: Audio System Sound Quality Diagnosis Audio System Diagnostic Mode

Also Check for

The vehicle position accuracy on the audio display depends on the GPS receiver in the smartphone, and the vehicle signals from F-CAN and the B-CAN