Compass Malfunction Mirror

The inside rearview mirror (ISRVM) uses 2 magnetic field sensors for compass direction. One sensor is for north and south, the other is for east and west. The ISRVM supplies a signal and low reference to each sensor. As the vehicle travels with or against the earths magnetic pull, there will be a change in voltage on one or both sensors. As a result of the change in voltage, the ISRVM changes the heading on the compass display. The internal fault detection for the compass is handled by the ISRVM.

Schematic Reference

Connector End View Reference

Component Connector End Views

Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, compass ON, verify that there is a compass reading on the display.

⇒	If the display is blank, replace the ISRVM.

⇒	If the display shows the letter C or CAL, perform the compass calibration procedure. Refer to Compass Calibration and Magnetic Variance.

2. Verify that the compass reading on the display is correct.

⇒	If not correct, perform the compass magnetic variation adjustment procedure. Refer to Compass Calibration and Magnetic Variance.

1. Ignition OFF, disconnect the harness connector at the inside rearview mirror (ISRVM).
2. Test for less than 1 ohm between the ground circuit terminal 8 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

⇒	Ignition ON, verify that a test lamp illuminates between the accessory voltage circuit terminal 13 and ground.

⇒	If the test lamp does not illuminate, repair the circuit for a short to ground or an open/high resistance.

3. If all circuits test normal, replace the ISRVM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for ISRVM replacement, setup, and programming