GM Service Manual Online
For 1990-2009 cars only

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

5-Volt Reference

B1580, B1590

B1580, B1590

B1580, B1590

--

Driver/Passenger Mirror Horizontal Position Sensor Signal

B1580

B1580

B1580

--

Driver/Passenger Mirror Vertical Position Sensor Signal

B1590

B1590

B1590

--

Left/Right Mirror Motor Down Control

B1600

1

B1600

--

Left/Right Mirror Motor Up Control

B1600

1

B1600

--

Left/Right Mirror Motor Left Control

B1605

1

B1605

--

Left/Right Mirror Motor Right Control

B1605

1

B1605

--

Low Reference

--

B1580, B1590

B1580, B1590

--

1. Power Mirror Malfunction

Circuit/System Description

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 driver door switch (DDS) sends a serial data message to the door modules when the mirror switch is activated to the up, down, left or right positions. When the door modules detect an active mirror command from the DDS, they will command the respective mirror motor in the appropriate direction. Each door module controls their respective mirror motors by applying a ground or voltage to the control circuit, depending on the desired mirror position.

Reference Information

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

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  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 Off, Driver, and Passenger.
  2. If the parameter does not cycle between the specified values, replace the DDSA.
  3. Observe the scan tool Mirror Direction Switch 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.
  4. If the parameter does not cycle between the specified values, replace the DDSA.
  5. Using the mirror directional switch operate the left and right outside mirrors up, down, left and right. The mirrors should move in the commanded directions.
  6. If a mirror does not move in all the commanded directions refer to, Mirror Motor Circuit Test.
  7. Operate the memory 1 and 2 recall switches. The outside rearview mirrors should adjust to the stored memory settings.
  8. If a mirror does not adjust to the stored memory setting refer to, Mirror Position Sensor Circuit Test.

Circuit/System Testing

Mirror Motor Circuit Test

  1. Ignition OFF, disconnect the X1 harness connector at the appropriate outside rearview mirror.
  2. Connect a test lamp between mirror motor UP control circuit terminal A and mirror motor DOWN control circuit terminal C.
  3. Command the mirror to the UP and DOWN positions with a scan tool. The test lamp should turn ON when commanding the Up and DOWN states.
  4. 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 circuit tests normal, replace the door module.
  5. Connect a test lamp between mirror motor LEFT control circuit terminal H and mirror motor RIGHT control circuit terminal F.
  6. Command the mirror to the LEFT and RIGHT positions with a scan tool. The test lamp should turn ON when commanding the LEFT and RIGHT states.
  7. 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 circuit tests normal, replace the door module.
  8. If all circuits test normal, test or replace the outside rearview mirror motor.

Mirror Position Sensor Circuit Test

  1. Ignition OFF, disconnect the X2 harness connector at the appropriate outside rearview mirror.
  2. Wait 1 minute, test for less than 1.0 ohm between the low reference circuit terminal C and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the door module.
  4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A and ground.
  5. 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 door module.
    If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the door module.
  6. Verify the listed scan tool parameter is greater than 4.8 volts.
  7. • Mirror Horizontal Position
    • Mirror Vertical Position
    If less than the specified range, test the listed signal circuit terminal for a short to ground. If the circuit tests normal, replace the door module.
    • Horizontal terminal D
    • Vertical terminal B
  8. Install a 3A fused jumper wire between the listed signal circuit terminal and the low reference circuit terminal 4. Verify the scan tool parameter is less than 0.2 volt.
  9. • Horizontal terminal D
    • Vertical terminal B
    If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the door module.
  10. If all circuits test normal, test or replace the outside rearview mirror motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Outside Rearview Mirror Motor Replacement
    •  Control Module References for DDM, PDM or DDS replacement, setup, and programming