The driver door module (DDM) and passenger door module (PDM) each provide motor control output functions for their respective mirrors. These output controls allow each door module to command their respective power mirrors in horizontal and vertical positions. The power mirror switch is integrated into DDM. When the DDM detects an active mirror command from the power mirror switch, the DDM will send a GMLAN serial data message to the PDM. Each door module will command there respective mirror motor in the appropriate direction by applying ground or voltage to the control circuit, depending on the desired mirror position.

Schematic Reference

Outside Rearview Mirror Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Outside Mirror Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information.

1. Ignition ON, observe the scan tool Mirror Select Switch parameter while cycling the mirror select switch between the left and right positions. The parameter should change between Idle, Right, and Left.

⇒	If the parameter does not cycle between the specified values, replace the DDM.

2. Observe the scan tool Mirror Horizontal Position and Mirror Vertical Position parameters. The reading should be between 0.2 volts and 4.8 volts and change as the mirror is moved, left, right, up, and down.

⇒	If not within the specified range or the parameter does not change as the mirror is moved, refer to Mirror Position Sensor Circuit Malfunction.

3. Observe the scan tool Mirror Motor parameter while cycling the mirror directional switch between the up, down, left and right positions. The parameter should change between Idle, Up, Down, Left, and Right.

⇒	If the parameter does not cycle between the specified values, replace the DDM.

4. Command the left and right outside mirror to move up, down, left and right using the mirror directional switch. The mirror should move in the commanded direction.

⇒	If either mirror does not move in all commanded directions, refer to Mirror Motor Circuit Malfunction.

Driver Mirror Position Sensor Circuit Malfunction

1. Ignition OFF, disconnect the X2 harness connector at the outside rearview mirror.
2. Wait 1 minute, test for less than 20.0 ohms between the low reference circuit terminal 12 and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the DDM.

3. Ignition ON, test for 4.8 - 5.2 volts between the 5-volt reference circuit terminal 9 and ground.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the DDM.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the DDM.

4. Install a 3-A fused jumper wire between the signal circuit terminal 11 and the 5-volt reference circuit terminal 9. Verify the scan tool Mirror Horizontal Position parameter is greater than 4.8 volts.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the DDM.

5. Install a 3-A fused jumper wire between the signal circuit terminal 10 and the 5-volt reference circuit terminal 9. Verify the scan tool Mirror Vertical Position parameter is greater than 4.8 volts.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the DDM.

6. Install a 3-A fused jumper wire between the signal circuit terminal 11 and the low reference circuit terminal 12. Verify the scan tool Mirror Horizontal Position parameter is less than 0.5 volt.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the DDM.

7. Install a 3-A fused jumper wire between the signal circuit terminal 10 and the low reference circuit terminal 12. Verify the scan tool Mirror Vertical Position parameter is less than 0.5 volt.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the DDM.

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

Passenger Mirror Position Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the outside rearview mirror.
2. Wait 1 minute, test for less than 20.0 ohms between the low reference circuit terminal 9 and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the PDM.

3. Ignition ON, test for 4.8 - 5.2 volts between the 5-volt reference circuit terminal 12 and ground.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PDM.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the PDM.

4. Install a 3-A fused jumper wire between the signal circuit terminal 11 and the 5-volt reference circuit terminal 9. Verify the scan tool Mirror Horizontal Position parameter is greater than 4.8 volts.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PDM.

5. Install a 3-A fused jumper wire between the signal circuit terminal 10 and the 5-volt reference circuit terminal 9. Verify the scan tool Mirror Vertical Position parameter is greater than 4.8 volts.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PDM.

6. Install a 3-A fused jumper wire between the signal circuit terminal 11 and the low reference circuit terminal 9. Verify the scan tool Mirror Horizontal Position parameter is less than 0.5 volt.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the PDM.

7. Install a 3-A fused jumper wire between the signal circuit terminal 10 and the low reference circuit terminal 9. Verify the scan tool Mirror Vertical Position parameter is less than 0.5 volt.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the PDM.

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

Driver Motor Circuit Malfunction

1. Ignition OFF, disconnect the X2 harness connector at the outside rearview mirror.
2. Connect a test lamp between the control circuit terminal 1 and the control circuit terminal 2.
3. Command the mirror UP and DOWN with a scan tool. The test lamp should turn ON when commanding the UP and DOWN states.

⇒	If the test lamp remains OFF during either of the commands, test for a short to voltage, short to ground, or an open/high resistance on either control circuit. If the circuits test normal, replace the DDM.

4. Connect a test lamp between the control circuit terminal 3 and the control circuit terminal 2.
5. Command the mirror LEFT and RIGHT with a scan tool. The test lamp should turn ON when commanding the LEFT and RIGHT states.

⇒	If the test lamp remains OFF during either of the commands, test for a short to voltage, short to ground, or an open/high resistance on either control circuit. If the circuits test normal, replace the DDM.

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

Passenger Motor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the outside rearview mirror.
2. Connect a test lamp between the control circuit terminal 1 and the control circuit terminal 2.
3. Command the mirror UP and DOWN with a scan tool. The test lamp should turn ON when commanding the Up and DOWN states.

⇒	If the test lamp remains OFF during either of the commands, test for a short to voltage, short to ground, or an open/high resistance on either control circuit. If the circuits test normal, replace the PDM.

4. Connect a test lamp between the control circuit terminal 3 and the control circuit terminal 2.
5. Command the mirror LEFT and RIGHT with a scan tool. The test lamp should turn ON when commanding the LEFT and RIGHT states.

⇒	If the test lamp remains OFF during either of the commands, test for a short to voltage, short to ground, or an open/high resistance on either control circuit. If the circuits test normal, replace the PDM.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.