GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 CTS 🢒 Body Systems 🢒 Mirrors 🢒 Heated Mirrors Inoperative - One

Test Description

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

  1. This step determines if the mirror heater feed circuit is shorted to battery positive voltage within the module.

    2.

  2. This step determines if the mirror heater feed circuit of the mirror pigtail harness is shorted to battery positive voltage.

Step

Action

Yes

No

Schematic Reference: Outside Rearview Mirror Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Verify that the Heated Mirrors Inoperative - One complaint is present.

Does the heated mirrors system operate as described in the Description and Operation?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn OFF the ignition
  2. Disconnect the C4 harness connector of the door module associated with the inoperative heated mirror.
  3. Ensure that all other harness connectors to the door module remain connected.
  4. Connect a test lamp between the heater feed circuit and the low reference circuit of the heated mirror at the door module pins.
  5. Turn ON the ignition, with the engine OFF

Does the test lamp illuminate?

Go to Step 9

Go to Step 4

4

While observing the test lamp, command the mirrors to heat by turning ON the rear window defroster.

Does the test lamp illuminate?

Go to Step 5

Go to Step 9

5

  1. Turn OFF the ignition.
  2. Connect the C4 harness connector of the door module associated with the inoperative heated mirror.
  3. Carefully remove the mirror face of the mirror that does not heat. Refer to Outside Rearview Mirror Glass Replacement .
  4. Disconnect the heated mirror harness connector from the mirror face.
  5. Connect a test lamp between the mirror heater circuits of the harness connector.
  6. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 7

Go to Step 6

6

While observing the test lamp, command the mirrors to heat by turning ON the rear window defroster.

Does the test lamp illuminate?

Go to Step 8

Go to Step 7

7

Inspect for poor connections at the harness connector of the inoperative heated mirror. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 12

8

Inspect for poor connections at the harness connector of the inoperative heated mirror face. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 10

9

Inspect for poor connections at the C4 harness connector of the door module associated with the inoperative outside rearview mirror. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 13

Go to Step 11

10

Replace the inoperative heated mirror face. Refer to Outside Rearview Mirror Glass Replacement .

Did you complete the replacement?

Go to Step 13

--

11

Replace the door module. Refer to Control Module References .

Did you complete the replacement?

Go to Step 13

--

12

Replace the inoperative heated mirror. Refer to Power Mirror Replacement .

Did you complete the replacement?

Go to Step 13

--

13

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2