GM Service Manual Online
For 1990-2009 cars only

Circuit 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 assembly (DDSA) 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 DDSA, they will command the respective mirror motor in the appropriate direction. Each door module commands their respective mirror motors by applying a ground or voltage to the control circuit, depending on the desired mirror position. For more detailed information concerning power mirror operation refer to Outside Mirror Description and Operation .

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B1600 Mirror Motor 1 (vertical) Circuit
    • DTC B1605 Mirror Motor 2 (horizontal) Circuit

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

    • The DDM or PDM detects a short to ground or voltage in the mirror motor control circuit.
    • The condition must be present for 2 seconds.

Action Taken When the DTC Sets

    • When DTC B1600 is present, the vertical mirror control will be disabled.
    • When DTC B1605 is present, the horizontal mirror control will be disabled.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • You issue a scan tool CLEAR DTCs command.

Diagnostic Aids

The following conditions may cause an intermittent malfunction:

    • There is an intermittent short to ground or voltage in a mirror motor control circuit.
    • A mirror motor is shorted internally.
    • Thoroughly inspect the wiring and connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis causing part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step

Action

Yes

No

Schematic Reference: Outside Rearview Mirror Schematics and Door Control Module Schematics

Connector End View Reference: Power Door Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Activate the mirror switch in the UP, DOWN, LEFT, and RIGHT directions for the appropriate outside rearview mirror.

Does the outside rearview mirror operate in all directions?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Disconnect the appropriate outside rearview mirror.
  2. Install a scan tool.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the appropriate mirror motors command parameter in the appropriate door module data list.
  5. Activate the mirror switch in the UP, DOWN, LEFT, and RIGHT directions.

Do all of the mirror motors command parameters change state?

Go to Step 7

Go to Step 4

4

Did the outside rearview mirror operate in the horizontal direction?

Go to Step 5

Go to Step 6

5

Test the appropriate vertical mirror motor control circuits for a short to ground or voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 8

6

Test the appropriate horizontal mirror motor control circuits for a short to ground or voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 8

7

Inspect for poor connections at the harness connector of the appropriate outside rearview mirror. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 9

8

Inspect for poor connections at the harness connector of the appropriate door module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

9

Replace the appropriate outside rearview mirror. Refer to Outside Rearview Mirror Replacement .

Did you complete the replacement?

Go to Step 11

--

10

Replace the appropriate door module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 11

--

11

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK