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

2

2

2

--

Driver/Passenger Horizontal Position Data Signal

2

2

2

--

Driver/Passenger Vertical Position Data Signal

2

2

2

--

Driver/Passenger Mirror Right Control

B1723, B1724

1

B1723, B1724

--

Driver/Passenger Mirror Common

B1723, B1724

1

B1723, B1724

--

Driver/Passenger Mirror Down Control

B1723, B1724

1

B1723, B1724

--

Low Reference

--

2

2

--

1. Power Mirror Malfunction

2. 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, voltage is supplied to the mirror vertical motor through the driver/passenger mirror motor right/down motors common circuit and ground is supplied through the driver/passenger mirror motor down control circuit. When the mirror is commanded down, voltage is supplied to the mirror vertical motor through the driver/passenger mirror motor down control circuit and ground is supplied through the driver/passenger mirror motor right/down motors common circuit.

Horizontal controls operate in the same manner with the driver/passenger mirror motor right/down motors common circuit supplying voltage and the driver/passenger mirror motor right control circuit supply a ground to the mirror horizontal motor when the mirror is commanded right. When the mirror is commanded left, voltage is supplied to the mirror horizontal motor through the driver/passenger mirror motor right control circuit and ground is supplied through the driver/passenger mirror motor right/down motors common circuit.

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

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.

Circuit/System Testing

  1. Ignition OFF, disconnect the X3 harness connector at the appropriate door module.
  2. Ignition ON, verify a test lamp does not illuminate between the following circuit terminals and ground:
  3. • 5-volt reference circuit terminal A2
    • Signal circuit terminal A5
    • Signal circuit terminal A6
    • Low reference circuit terminal A4
    If the test lamp illuminates, test the appropriate circuit for a short to voltage.
  4. Ignition OFF, test for infinite resistance between the following circuits and ground:
  5. • 5-volt reference circuit terminal A2
    • Signal circuit terminal A5
    • Signal circuit terminal A6
    • Low reference circuit terminal A4
    If less than the specified value, test the appropriate circuit for a short to ground.
  6. Test for 4K-7K ohms between the 5-volt reference circuit terminal A2 and the low reference circuit terminal A4.
  7. If not within the specified range, test the 5-volt reference circuit and the low reference circuit for an open/high resistance. If the circuits test normal, test or replace the rearview mirror motor.
  8. Test for 1K-7K ohms between the 5-volt reference circuit terminal A2 and the signal circuit terminal A5.
  9. If not within the specified range, test the signal circuit for an open/high resistance. If the circuits test normal, test or replace the rearview mirror motor.
  10. Test for 1K-7K ohms between the 5-volt reference circuit terminal A2 and the signal circuit terminal A6.
  11. If not within the specified range, test the signal circuit for an open/high resistance. If the circuits test normal, test or replace the rearview mirror motor.
  12. If all circuits test normal, replace the door module.

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