Power Mirrors Inoperative

Power Mirrors Inoperative

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.

Diagnostic Fault Information






Circuit/System Description

The outside rearview mirror switch supplies both voltage and ground to the outside rearview mirror motors. When the outside rearview mirror switch is being pressed the switch supplies the voltage and ground to the proper circuits to engage the proper mirror motor.

Diagnostic Aids

* The rearview mirror motors are bi-directional. When voltage and ground are reversed the motor will also reverse in direction.
* The rearview mirror control circuits are normally open at the rearview mirror switch.

Circuit/System Verification

Ignition ON, observe the operation of each outside rearview mirror while using the outside rearview mirror switch. The appropriate mirror should move in the direction commanded.

Circuit/System Testing

Outside Rearview Mirror Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the outside rearview mirror switch.
2. Test for less than 1 ohm between the ground circuit terminal D and ground.

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

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal E and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the B+ circuit fuse is open, test the control circuit for a short to ground.

4. If all circuits test normal, test or replace the outside rearview mirror switch.

Outside Rearview Mirror Motor Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate outside rearview mirror motor.
2. Test for infinite resistance between the mirror control circuits and ground.

• If less than the specified range, test the control circuits for a short to ground.

3. Ignition ON, connect a test lamp between the control circuit for the particular motor and the common control circuit for the mirror motors. Operate the mirror motor by using the outside rearview mirror switch. The test lamp should illuminate with each command.

• If the test lamp is always OFF, test the control circuits for a short to ground or an open/high resistance. If the circuits test normal, test or replace the rearview mirror switch.
• If the test lamp is always ON, test the control circuits for a short to voltage. If the circuits test normal, test or replace the rearview mirror switch.

4. If all circuits test normal, test or replace the appropriate outside rearview mirror motor.

Component Testing

Outside Rearview Mirror Switch

1. Ignition OFF, disconnect the harness connector at the outside rearview mirror switch.
2. Test for infinite resistance between all of the signal terminals and the voltage supply terminal and the ground circuit with the switch in the open position.

• If less than the specified range, replace the rearview mirror switch.

3. Test for less than 1 ohm between all of the control terminals and ground with the outside rearview mirror switch in the proper positions.

• If greater than the specified range, test the ground circuit for an open/high resistance. If the circuits test normal, replace the rearview mirror switch.

Outside Rearview Mirror Motor

1. Ignition OFF, disconnect the harness connector at the outside rearview mirror motor.
2. Test for 29-90 ohms between the control terminal and the ground terminal of the rearview mirror motor.

• If the resistance is not within the specified range, replace the rearview mirror motor.

Repair Instructions

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

* Power Mirror Replacement
* Power Mirror Switch Replacement