Compass Malfunction (Mirror)

Compass Malfunction (Mirror)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (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.

Reference Information
Schematic Reference

* Instrument Cluster Schematics (Instrument Cluster Schematics)
* Inside Rearview Mirror Schematics (Inside Rearview Mirror Schematics)

Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

* Automatic Day-Night Mirror Description and Operation (Automatic Day-Night Mirror)
* Instrument Cluster Description and Operation (Instrument Cluster)

Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

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 (Testing and Inspection).

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 (Testing and Inspection).

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 (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning) for ISRVM replacement, setup, and programming