Compass Malfunction (Mirror)

Compass Malfunction (Mirror)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

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.

Circuit/System Verification

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.

Circuit/System Testing

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.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests