GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the power sunroof system check performed?

--

Go to Step 2

Go to Power Sunroof System Check

2

  1. Turn the ignition switch on.
  2. Using a test lamp, connect by backprobing between C 200 terminal A9 and ground.

Is the test light on?

--

Go to Step 8

Go to Step 6

3

  1. Remove the interior lamp and multi-function switch from the headliner and leave the interior lamp and multi-function switch harness connector connected.
  2. Using a J 39200 digital multimeter (DMM), measure the voltage by backprobing between the interior lamp and multi-function switch connector C4 terminal H and ground.

Is the voltage measured within the specified range?

4.5-5.5V

Go to Step 4

Go to Step 19

4

Using a J 39200 DMM, measure the voltage by backprobing between the interior lamp and multi-function switch harness connector C4 terminal F and ground.

Is the voltage measured within the specified range?

(Note: if the J 39200 DMM displays B+, then go to step 39).

4.5-5.5V

Go to Step 5

Go to Step 23

5

Using a J 39200 DMM, measure the voltage by backprobing between the interior lamp and multi-function switch harness connector C4 terminals H and C.

Is the voltage measured within the specified range?

4.5-5.5V

Go to Step 10

Go to Step 26

6

Check the SUNROOF Fuse located in the fuse block.

Is the SUNROOF Fuse open?

--

Go to Step 7

Go to Step 8

7

Repair short to ground in CKT 541.

Is the repair complete?

--

Go to Power Sunroof System Check

--

8

Using a test lamp, connect by backprobing between C398 terminal A and ground.

Is the test lamp on?

--

Go to Step 9

Go to Step 28

9

  1. Turn the ignition switch off.
  2. Disconnect the sunroof module electrical connector C2.
  3. Turn the ignition switch on.
  4. Using a test lamp and a J 35616 kit, connect between the sunroof module harness connector C2 terminals B and D.

Is the test lamp on?

--

Go to Step 3

Go to Step 29

10

  1. Connect a test lamp by backprobing between the sunroof module harness connector C2 terminal  A and ground.
  2. While observing the test lamp, press and hold close on the interior lamp and multi-function switch.

Is the test lamp on?

--

Go to Step 11

Go to Step 22

11

  1. Connect a test lamp by backprobing between the sunroof module harness connector C2 terminal C and ground.
  2. While observing the test lamp, press and hold open on the interior lamp and multi-function switch.

Is the test lamp on?

--

Go to Step 14

Go to Step 22

12

  1. Turn the ignition switch off.
  2. Disconnect the sunroof actuator connector C3.
  3. Connect a test lamp between the sunroof actuator harness connector C3 terminals A and B.
  4. While observing the test light, press and hold close on the interior lamp and multi-function switch.

Is the test lamp on?

--

Go to Step 13

Go to Step 30

13

  1. Leave the test lamp connected (from previous step).
  2. While observing the test lamp, press and hold open on the interior lamp and multi-function switch.

Is the test lamp on?

--

Go to Step 18

Go to Step 30

14

  1. Turn the ignition switch off.
  2. Reconnect the sunroof module.
  3. Turn the ignition switch on.
  4. Using a J 39200 DMM, measure the voltage by backprobing between the limit switch module harness connector C5 terminal C and ground.

Is the voltage measured within the specified range? (Note: if voltage measured is B+, then go to step 39).

4.5-5.5V

Go to Step 15

Go to Step 31

15

Using a J 39200 DMM, measure the voltage by backprobing between the limit switch module harness connector C4 terminal C and ground.

Is the voltage measured within the specified range? (Important: if voltage measured is B+, then go to step 39).

4.5-5.5V

Go to Step 16

Go to Step 34

16

Using a J 39200 DMM, measure the voltage by backprobing between the limit switch module harness connector C5 terminal A and ground.

Is the voltage measured within the specified range? (Important: if voltage measured is B+, then go to step 39).

4.5-5.5V

Go to Step 17

Go to Step 36

17

Using a J 39200 DMM, measure the voltage by backprobing between the limit switch module harness connector C4 terminal B and connector C5 terminal A.

Is the voltage measured within the specified range?

4.5-5.5V

Go to Step 12

Go to Step 38

18

Replace the sunroof actuator. Refer to Sunroof Actuator Replacement .

Is the repair complete?

--

Go to Power Sunroof System Check

--

19

  1. Disconnect the interior lamp and multi-function switch electrical connector.
  2. Using a J 39200 DMM and a J 35616 kit, measure the voltage between the interior lamp and multi-function switch harness connector C4 terminal H and ground.

Is the voltage measured within the specified range?

4.5-5.5V

Go to Step 21

Go to Step 20

20

Locate open or short to ground in CKT 100.

Is there an open or short to ground in CKT 100?

--

Go to Step 40

Go to Step 22

21

Replace the interior lamp and multi-function switch. Refer to Sunroof Switch Replacement .

Is the repair complete?

--

Go to Power Sunroof System Check

--

22

Replace the sunroof module. Refer to Power Sunroof Module Replacement .

Is the repair complete?

--

Go to Power Sunroof System Check

--

23

  1. Disconnect the interior lamp and multi-function switch electrical connector.
  2. Using a J 39200 DMM and a J 35616 kit, measure the voltage between the interior lamp and multi-function switch harness connector terminal F and ground.

Is the measured voltage within the specified value?

4.5-5.5V

Go to Step 21

Go to Step 24

24

Repair open or short to ground in CKT 110.

Is the repair complete?

--

Go to Power Sunroof System Check

--

25

Repair the open or short to ground.

Is the repair complete?

--

Go to Power Sunroof System Check

--

26

  1. Turn the ignition switch off.
  2. Disconnect the interior lamp and multi-function switch electrical connector.
  3. Disconnect the sunroof module electrical connector C1.
  4. Using a J 39200 DMM, measure the resistance between the interior lamp and multi-function switch harness connector terminal G and the sunroof module harness connector C1 terminal 5.

Is the measured resistance within the specified range?

Less than 2ohms

Go to Step 22

Go to Step 27

27

Repair poor connection or open in CKT 128.

Is the repair complete?

--

Go to Power Sunroof System Check

--

28

Repair poor connection or open in CKT 541.

Is the repair complete?

--

Go to Power Sunroof System Check

--

29

Repair poor connection or open in CKT 650.

Is the repair complete?

--

Go to Power Sunroof System Check

--

30

Repair poor connection or open in CKT 127 or CKT 129.

Is the repair complete?

--

Go to Power Sunroof System Check

--

31

  1. Disconnect the limit switch module electrical connector C4 and C5.
  2. Using a J 39200 DMM and a J 35616 kit, measure the voltage between the limit switch module harness connector C5 terminal A and ground.

Is the voltage measured within the specified range?

4.5-5.5V

Go to Step 33

Go to Step 32

32

Locate open or short to ground in the RED wire between the sunroof module harness connector C1 terminal 2 and the limit switch module harness connector C5 terminal A.

Is there an open or short to ground in the RED wire?

--

Go to Step 41

Go to Step 22

33

Replace the limit switch module.

Is the repair complete?

--

Go to Power Sunroof System Check

--

34

  1. Disconnect the limit switch module harness connector C4 and C5.
  2. Using a J 39200 DMM and a J 35616 kit, measure the voltage between the limit switch module harness connector C4 terminal C and ground.

Is the voltage measured within the specified range?

4.5-5.5V

Go to Step 33

Go to Step 35

35

Locate open or short to ground in WHT wire between the sunroof module harness connector C1 terminal 8 and the limit switch module harness connector C4 terminal C.

Is there an open or short to ground in the WHT wire?

--

Go to Step 42

Go to Step 22

36

  1. Disconnect the limit switch module harness connector C4 and C5.
  2. Using a J 39200 DMM and a J 35616 kit, measure the voltage between the limit switch module harness connector C5 terminal A and ground.

Is the voltage measured within the specified range?

5.5-6.5V

Go to Step 33

Go to Step 37

37

Locate open or short to ground in the RED wire between the sunroof module harness connector C1 terminal 2 and the limit switch module harness connector C5 terminal A.

Is there an open or short to ground in the RED wire?

--

Go to Step 43

Go to Step 22

38

Locate open in the BLK/WHT wire between the sunroof module harness connector C1 terminal 1 and the limit switch module harness connector C4 terminal B and connector C5 terminal C.

Is there an open in the BLK/WHT wire?

--

Go to Step 41

Go to Step 22

39

Repair the short to B+.

Is the repair complete?

--

Go to Power Sunroof System Check

--

40

Repair the open or short to ground in CKT 100.

Is the repair complete?

--

Go to Power Sunroof System Check

--

41

Repair open or short to ground in the BLK/WHT wire between the sunroof module harness connector C1 terminal 1 and the limit switch module harness connector C4 terminal B and connector C5 terminal C.

Is the repair complete?

--

Go to Power Sunroof System Check

--

42

Repair open or short to ground in the WHT wire between the sunroof module harness connector C1 terminal 8 and the limit switch module harness connector C4 terminal C.

Is the repair complete?

--

Go to Power Sunroof System Check

--

43

Repair open or short to ground in the RED wire between the sunroof module harness connector C1 terminal 2 and the limit switch module harness connector C5 terminal A.

Is the repair complete?

--

Go to Power Sunroof System Check

--