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

Position Sensor 5-Volt Reference

B1580, B1590

B1580, B1590

B1580, B1590

--

Driver/Passenger Mirror Horizontal Position Sensor Signal

B1580

1

B1580

--

Driver/Passenger Mirror Vertical Position Sensor Signal

B1590

1

B1590

--

Left/Right Mirror Motor Horizontal Control

B1544 04, B1605 02

B1544 04, B1605 04

B1605 01

--

Left/Right Mirror Motor Common Control

B1544 04, B1600 04, B1605 04, B1544 02

B1544 04, B1600 04, B1605 04

B1544 01

--

Left/Right Mirror Motor Vertical Control

B1544 04, B1600 02

B1544 04, B1600 04

B1600 01

--

Low Reference

B1580, B1590

B1580, B1590

B1580, B1590

--

1. Memory Mirror Malfunction

Circuit/System Description

The Driver Door Module (DDM) or Passenger Door Module (PDM) controls the mirror horizontal and vertical motors through the use of bi-directional motor controls. When the mirror is commanded up and down, voltage or ground is supplied to the mirror vertical motor through the mirror motor up/down control circuit and voltage or ground is supplied through the mirror motor common control circuit.

Horizontal controls operate in the same manner with the mirror motor left/right control circuit supplying voltage or ground and the mirror motor common control circuit suppling voltage or ground to the mirror horizontal motor when the mirror is commanded right and left.

The DDM and PDM determine the position of the outside rearview mirrors based on inputs from two mirror position sensors, one for vertical position, the other for horizontal position. 5 volts is applied to each sensor through a shared 5-volt reference circuit and a shared low reference circuit supplies ground. Each sensor has an individual signal circuit which provides position voltage to the DDM/PDM.

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 Idle, Right, and Left.
  2. If the parameter does not cycle between the specified values, replace the DDM.
  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.
  4. If the parameter does not cycle between the specified values, replace the DDM.
  5. Using the mirror directional switch operate the left and right outside mirrors to move 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 outside rearview mirror.
  2. Connect a test lamp between the control circuit terminal 11 and the control circuit terminal 10.
  3. Ignition ON, command the mirror LEFT and RIGHT with a scan tool. The test lamp should turn ON when commanding the LEFT and RIGHT states.
  4. If the test lamp remains OFF during either of the commands, test for a short to ground or an open/high resistance on either control circuits. If the circuits test normal, replace the door module.
  5. Connect a test lamp between the control circuit terminal 9 and the control circuit terminal 10.
  6. Ignition ON, command the mirror UP and DOWN with a scan tool. The test lamp should turn ON when commanding the UP and DOWN states.
  7. If the test lamp remains OFF during either of the commands, test for a short to ground or an open/high resistance on either control circuits. If the circuits test 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 7 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 appropriate door module.
  4. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 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 appropriate 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. Install a 3A fused jumper wire between the signal circuit terminal 5 and the 5-volt reference circuit terminal 3. Verify the scan tool Mirror Vertical Position parameter is greater than 4.8 volts.
  7. 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 door module.
  8. Install a 3A fused jumper wire between the signal circuit terminal 6 and the 5-volt reference circuit terminal 3. Verify the scan tool Mirror Horizontal Position parameter is greater than 4.8 volts.
  9. 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 door module.
  10. Install a 3A fused jumper wire between the signal circuit terminal 5 and the low reference circuit terminal 7. Verify the scan tool Mirror Vertical Position parameter is less than 0.2 volt.
  11. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the door module.
  12. Install a 3A fused jumper wire between the signal circuit terminal 6 and the low reference circuit terminal 7. Verify the scan tool Mirror Horizontal Position parameter is less than 0.2 volt.
  13. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the door module.
  14. 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 or PDM replacement, setup, and programming