GM Service Manual Online
For 1990-2009 cars only

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step determines if the mirror sensors are capable of sensing mirror position changes.

  2. This step verifies that the module has the appropriate voltage available at both the vertical and horizontal position sensor signal circuits. With the door module harness connector C4 disconnected, both the horizontal and the vertical position sensor signal circuits within the module should display their highest value of 4.5-5.5 volts.

Step

Action

Value(s)

Yes

No

Schematic Reference: Outside Rearview Mirror Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Enable the personalization function by performing the following steps:
  2. 1.1. Turn ON the ignition, with the engine OFF.
    1.2. Adjust both outside rearview mirrors to your preference.
    1.3. With the memory switch, set the personalization recall to your adjustments.
  3. Adjust both outside rearview mirrors to an extreme position.
  4. Press the memory button that was previously programmed.

Did both outside rearview mirrors move back to the programmed setting?

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

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe both the Vertical Sensor and Horizontal Sensor parameters in the Driver Door Module (DDM) Data list.
  4. Operate the suspect mirror to the limits of travel in both the vertical and horizontal directions.

Did the scan tool indicate the voltage for both sensors changes and is within the specified range?

0.5-4.5 V

Go to Step 8

Go to Step 4

4

  1. Turn the ignition OFF.
  2. Disconnect the harness connector C4 of the door module associated with the inoperative mirror.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage of the mirror 5-volt reference circuit for the inoperative mirror at the door module pin.

Is the voltage indicated within the specified range?

4.5-5.5 V

Go to Step 5

Go to Step 10

5

With a scan tool, observe both the Vertical Sensor and Horizontal Sensor parameters in the Driver Door Module data list.

Is the voltage indicated for each sensor within the specified range?

4.5-5.5 V

Go to Step 6

Go to Step 10

6

  1. Install a 3-amp fused jumper between, first the mirror sensor return circuit and the horizontal sensor signal circuit at the door module pins, and then between the mirror sensor return circuit and the vertical sensor signal circuit at the door module pins.
  2. With the scan tool, observe both the Vertical Sensor and Horizontal Sensor parameters.

Did the scan tool indicate the voltage for each sensor was within the specified range?

0-0.5 V

Go to Step 7

Go to Step 10

7

Inspect for poor connections at the harness connector of the 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?

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Go to Step 11

Go to Step 9

8

Inspect for poor connections at the harness connector of the 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?

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Go to Step 11

Go to Step 10

9

Replace the inoperative outside rearview mirror. Refer to Power Mirror Replacement .

Did you complete the replacement?

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Go to Step 11

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10

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

Did you complete the replacement?

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Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2