Mirror Compass Display Inoperative or Inaccurate

Mirror Compass Display Inoperative or Inaccurate

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview






Circuit/System Description

The compass relies on a magnetic field sensor built into the rearview mirror for the input of the correct direction the vehicle is facing.

Diagnostic Aids

* Before calibrating the compass, drive the vehicle to an open area that is magnetically clean or free of large metallic objects such as high tension power lines or large steel buildings.
* Before calibrating the compass, make sure the mirror has the correct zone number.
* Make sure the automatic day-night feature of the inside rearview mirror operates correctly.

Circuit/System Verification

Test drive the vehicle in an open area away from larger buildings and power lines. Drive around in a circle at a speed of less than 8 km/h (5 mph). Observe the compass display in the rearview mirror. The compass display should change between the proper directions the vehicle is facing.

Circuit/System Testing

1. Ignition ON, observe the compass display for either having an incorrect reading, a letter "C" or "CAL" or the compass display that is totally blank.

• If the compass display reads an incorrect reading or a letter "C" or "CAL" perform the compass reprogramming procedure.

2. Ignition OFF, disconnect the harness connector at the inside rearview mirror.
3. Test for less than 1 ohm of resistance between the ground circuit and ground.

• If greater than 1 ohm, test the ground circuit for a short to voltage or an open/high resistance.

4. Ignition ON, verify that a test lamp illuminates between the accessory voltage supply circuit and ground.

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

5. If the compass display is totally blank, replace the rearview mirror.

Repair Instructions

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

* Compass Calibration and Magnetic Variance
* Refer to Programming and Relearning for setup and programming. Programming and Relearning