GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The mirror position sensors are potentiometers powered by the door module for the mirror. Both the driver door module (DDM), and the passenger door module (PDM), determine the horizontal and vertical position of their respective mirror based on the signal voltages from the mirror position sensors.

Conditions for Running the DTC

The DDM and the PDM must be powered.

Conditions for Setting the DTC

These DTCs will set if:

    • A mirror position sensor signal voltage is below 0.25 V for 2 seconds.
    • A mirror position sensor signal voltage is above 4.75 V for 2 seconds.

Action Taken When the DTC Sets

The door module will de-activate and ignore the failed sensor. Manual movements to the affected position will not be disabled.

Conditions for Clearing the DTC

The current DTC clears when the door module no longer senses the failure. The DTC is stored as a history DTC. The history DTC will clear either after 50 OFF/ON ignition cycles without a repeated failure, or in response to a scan tool command.

Diagnostic Aids

If the Personalization Option in the Dash Integration Module (DIM) is activated on a vehicle that does not have the A45 Memory Mirrors option, DTCs B1581, B1591, B1611, and B1621 will be erroneously set. If these DTCs are set on a vehicle that does not have A45, refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System to deactivate the option.

After readjusting the mirror positions, be sure to set the memory switch to the new positions.

Step

Action

Value(s)

Yes

No

Schematic Reference: Outside Rearview Mirror Schematics

1

Did you perform the Door Systems Diagnostic System Check?

--

Go to Step  2

Go to Diagnostic System Check - Door Systems

2

Is the vehicle equipped with the A45 Memory Mirrors option?

--

Go to Step  4

Go to Step  3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, navigate to the Dash Integration Module (DIM).
  4. Select Special Functions.
  5. Select Set Options.
  6. Select the appropriate Personalization.
  7. Follow the on screen instructions to deactivate the option.

Did you complete the deactivation?

--

Go to Step  10

Go to Body Control Module (BCM) Programming/RPO Configuration

in Body Control System

4

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Using the mirror position switch, move the mirror to the limits of travel.
  4. With the scan tool, observe the applicable mirror position sensor parameter in the Driver Door Module Data list .

Does the scan tool indicate the voltage changes and is within the specified range?

0.25-4.75 V

Go to Step  10

Go to Step  5

5

  1. Turn OFF the ignition.
  2. Disconnect the C3 harness connector from the door module associated with the inoperative mirror.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the position sensor 5 volt reference circuit at the door module pin.

Does the voltage measure near the specified value?

4.75-5.50 V

Go to Step  6

Go to Step  9

6

  1. Turn OFF the ignition.
  2. Connect a 3 amp fused jumper wire between the applicable mirror position sensor signal circuit and the mirror sensor low reference circuit at the door module pins.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the applicable mirror position parameter.

Does the scan tool indicate the voltage is near the specified value?

0-0.25 V

Go to Step  7

Go to Step  9

7

Inspect for poor connections at the C3 harness connector of the door module associated with the inoperative 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  10

Go to Step  8

8

Replace the appropriate mirror. Refer to Power Mirror Replacement .

Did you complete the replacement?

--

Go to Step  10

--

9

Replace the appropriate door module. Refer to Door Control Module Replacement .

Did you complete the replacement?

--

Go to Step  10

--

10

  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