GM Service Manual Online
For 1990-2009 cars only

Test Description

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

  1. Will determine if the malfunction is in the mirror heater circuits or the associated door module.

Step

Action

Yes

No

1

Did you Perform the Diagnostic System Check - Power Door Systems?

Go to Step 2

Go to Diagnostic System Check - Power Door Systems

2

  1. Turn OFF the ignition.
  2. Remove the mirror face (glass) from the mirror that does not heat. Refer to Mirror Face Replacement - Outside Electrochromatic .
  3. Disconnect the heated mirror harness connector from the mirror face.
  4. Connect a test lamp between the mirror heater circuits.
  5. Turn the ignition ON, with the engine OFF
  6. Command the mirror to heat by turning the rear defroster on.

Does the test lamp illuminate?

Go to Step 4

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the mirror heater connector of the inoperative mirror from its associated door module.
  3. Test the mirror heater circuits for opens and shorts to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the problem?

Go to Step 8

Go to Step 5

4

Inspect for poor connections at the harness connector of the inoperative outside rear view mirror face. 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 8

Go to Step 6

5

Inspect for poor connections at the harness connector of the door module that is 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 8

Go to Step 7

6

Replace the inoperative outside rear view mirror face. Refer to Mirror Face Replacement - Outside Electrochromatic .

Did you complete the replacement?

Go to Step 8

--

7

Replace the door module of the inoperative mirror. Refer to Door Control Module Replacement .

Did you complete the replacement?

Go to Step 8

--

8

Operate the system in order to verify the repair

Did you correct the condition?

System OK

Go to Step 2