Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Outside Rearview Mirror Switch Supply Voltage Circuit | 1 | 1 | -- | -- |
Outside Rearview Mirror Ground Supply Circuit | -- | 1 | 1 | -- |
Rearview Mirror Motor Signal Circuits | 2 | 2 | 2 | -- |
1. Rearview Mirror Functions Inoperative - ALL 2. Rearview Mirror Functions Inoperative - ONE | ||||
Circuit/System Description
The outside rearview mirror switch supplies both voltage and ground to the rearview mirror motors. When the 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 have a circuit breakers installed in the motors. The circuit breakers will open the circuit after 30 seconds of continuous voltage. |
| • | 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. |
Reference Information
Schematic Reference
Outside Rearview Mirror Schematics
Electrical Information Reference
Circuit/System Verification
Ignition ON, observe the outside rearview mirror while operating the rearview mirror switch. The mirror should move in all directions commanded. If no movements are observed check the outside rearview mirror switch. If the rearview mirror switch is okay, check the outside rearview mirror motor.
Circuit/System Testing
Outside Rearview Mirror Switch Circuit Testing
- Ignition OFF, disconnect the harness connector at the outside rearview mirror switch.
- Test for less than 1 ohm of resistance between the ground circuit and ground.
- Ignition ON, verify that a test lamp illuminates between the voltage supply circuit and ground.
- If all circuits test normal, test or replace the outside rearview mirror switch.
| ⇒ | If greater than 1 ohm, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp does not illuminate, repair the voltage supply circuit for a short to ground or an open/high resistance. If the voltage supply circuit fuse is open, also test the signal circuit for a short to ground. |
Outside Rearview Mirror Motor Circuit Testing
- Ignition OFF, disconnect the harness connector at the outside rearview mirror motor.
- Test for infinite resistance between the mirror control circuits and ground.
- Install 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 the mirror switch. The test lamp should illuminate with each command.
- If all circuits test normal, test or replace the outside rearview mirror motor.
| ⇒ | If less than infinite resistance, test the control circuits for a short to ground. |
| ⇒ | If the test lamp does not illuminate, test the motor control circuits for an open/high resistance or a short to ground. If the circuits test normal, test or replace the rearview mirror switch. |
| ⇒ | If the test lamp stays ON constantly, test the motor control circuit for a short to voltage. If the circuits test normal, test or replace the rearview mirror switch. |
Component Testing
Outside Rearview Mirror Switch Testing
- Ignition OFF, disconnect the harness connector at the outside rearview mirror switch.
- 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.
- Test for less than 1 ohm of resistance between all of the control terminals and ground with the outside rearview mirror switch in the proper positions.
| ⇒ | If less than infinite resistance, replace the rearview mirror switch. |
| ⇒ | If greater than 1 ohm, test the ground circuit for an open/high resistance. If the circuits test normal, replace the rearview mirror switch. |
Outside Rearview Mirror Motor Testing
- Ignition OFF, disconnect the harness connector at the outside rearview mirror motor.
- Test for 29-90 ohms of resistance 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.
