GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Power Sunroof System Check?

--

Go to Step 2

Go to Power Sunroof System Check

2

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof control module connector C1 and connector C2.
  3. Turn the ignition switch to the RUN position.
  4. Connect a test lamp between the sunroof control module connector C1 terminal C and ground.

Does the test lamp light?

--

Go to Step 3

Go to Step 4

3

Connect a test lamp between the sunroof control module connector C1 terminal C and terminal D.

Does the test lamp light?

--

Go to Step 5

Go to Step 6

4

Repair the open or short in CKT 141 (BRN). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Sunroof System Check

--

5

Connect a test lamp between the sunroof control module connector C1 terminal C and connector C2 terminal 6.

Does the test lamp light?

--

Go to Step 8

Go to Step 7

6

  1. Inspect the connector C308 terminal A for proper contact.
  2. If the contact is OK, repair the CKT 141 (BLK) for an open or a short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Sunroof System Check

--

7

Connect a test lamp between the sunroof control module connector C1 terminal C and connector C2 terminal 7.

Does the test lamp light?

--

Go to Step 10

Go to Step 9

8

Repair CKT 100 for a short to ground. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Power Sunroof System Check

--

9

  1. Open the sunroof by performing the following steps:
  2. 1.1. Partially lower the headliner.
    1.2. Release the clutch.
    1.3. Manually crank the sunroof using a 4 mm hex wrench.
  3. Use the J 39200 DMM, in order to measure the resistance between the sunroof control module connector C2 terminal 5 and terminal 6.

Is the resistance infinite?

--

Go to Step 12

Go to Step 11

10

Test for short between CKT 128 (DK BLU) and CKT 100 (BRN).

Was a short found?

--

Go to Step 11

Go to Step 12

11

Repair short between CKT 128 (DK BLU) and CKT 100 (BRN).

Is the repair complete?

--

Go to Power Sunroof System Check

Go to Step 12

12

If Circuits 128 (DK BLU) and CKT 100 (BRN) are OK, Replace the Sunroof Switch. Refer to Sunroof Switch Replacement .

Is the repair complete?

--

Go to Power Sunroof System Check

Go to Step 13

13

Use the J 39200 DMM, in order to measure the resistance between the sunroof control module connector C2 terminal 5 and terminal 7.

Is the resistance infinite?

--

Go to Step 14

Go to Step 15

14

Use the J 39200 DMM, in order to measure the resistance between the sunroof control module connector C2 terminal 8 and ground.

Is the resistance infinite?

--

Go to Step 15

Go to Step 16

15

Use the J 39200 DMM, in order to measure the resistance between the sunroof control module connector C2 terminal 8 and terminal 1.

Is the resistance infinite?

--

Go to Step 17

Go to Step 18

16

  1. Test CKT 132 for a short to ground.
  2. If the circuit is OK, replace the sunroof motor. Refer to Power Sunroof Motor Replacement .

Is the repair complete?

--

Go to Power Sunroof System Check

Go to Step 18

17

  1. Hold the sunroof switch to the CLOSE position.
  2. Use the J 39200 DMM in order to measure the resistance between the sunroof control module connector C2 terminal 5 and terminal 7.
  3. Hold the sunroof switch to the OPEN position.
  4. Using the J 39200 DMM, measure the resistance between terminal 5 and terminal 7.

Is the resistance less than the specified value for each test?

5 ohms

Go to Step 19

Go to Step 20

18

  1. Test for a short between CKT 132 (RED) and CKT 133 (YEL).
  2. Repair short in CKT 132 (RED) and CKT 133 (YEL). Refer to Power Sunroof Motor Replacement in Wiring Repairs.
  3. If the circuits are OK, replace the sunroof motor. Refer to Power Sunroof Motor Replacement .

Is the repair complete?

--

Go to Power Sunroof System Check

--

19

  1. Close the sunroof.
  2. Connect a fused jumper between the sunroof control module connector C1 terminal C and terminal B.
  3. Connect a fused jumper between the sunroof control module connector C1 terminal A and terminal D.

Does the sunroof motor operate?

--

Go to Step 22

Go to Step 21

20

  1. Test CKT 100 or CKT 110 and CKT 128 for an open.
  2. Inspect for proper terminal contact at the sunroof switch connectors.
  3. If all of the circuits and connectors are OK, replace the sunroof switch. Refer to Sunroof Switch Replacement .

Is the repair complete?

--

Go to Power Sunroof System Check

--

21

  1. Test CKT 127 and CKT 129 for an open or a short to ground.
  2. If the circuits are OK, replace the sunroof motor. Refer to Power Sunroof Motor Replacement .

Is the repair complete?

--

Go to Power Sunroof System Check

--

22

  1. Test the sunroof control module connector C1 for proper terminal contact.
  2. If the contact is OK, replace the sunroof control module.

Is the repair complete?

--

Go to Power Sunroof System Check

--