GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you review the automatic day/night mirrors circuit description and perform the necessary inspections?

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Go to Step 2

Go to Symptoms

2

Verify that the automatic day/night mirrors are inoperative.

Do the automatic day/night mirrors operate normally?

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

Go to Step 3

3

Inspect the 10A HVAC fuse in the underhood fuse block.

Is the fuse blown?

--

Go to Step 4

Go to Step 7

4

  1. Turn the ignition switch to the RUN position.
  2. Test CKT 341 (BRN) for a short to ground between the IP fuse block and cavity 1 of the automatic day/night inside mirror.

Is a short present?

--

Go to Step 5

Go to Step 6

5

Repair the short to ground in CKT 341 (BRN).

Did you complete the repair?

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Go to Step 12

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6

Replace the 10A HVAC fuse in the underhood fuse block.

Did you complete the repair?

--

Go to Step 12

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7

  1. Turn the ignition switch to the RUN position.
  2. Connect a test lamp between the automatic day/night mirror cavity 1 and ground.

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 8

8

Repair the open in CKT 341 (BRN) between the IP fuse block and cavity 1 of the automatic day/night inside mirror.

Did you complete the repair?

--

Go to Step 12

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9

Connect a test lamp between B+ and cavity 2 of the automatic day/night inside rear view mirror.

Does the test lamp illuminate?

--

Go to Step 10

Go to Step 11

10

Replace the automatic day/night inside rear view mirror. Refer to Inside Rearview Mirror Replacement .

Did you complete the repair?

--

Go to Step 12

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11

Repair the open in CKT 1850 (BLK) between the automatic day/night inside rear view mirror and G202.

Did you complete the repair?

--

Go to Step 12

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12

Operate the system in order to verify the repair.

Did you find and correct the condition?

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System OK

Go to Step 3