GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Inspect the SUNROOF fuse.

Is the fuse open?

--

Go to Step 2

Go to Step 3

2

Repair a short to ground in circuit 343.

Has the repair been made and the system rechecked?

--

System OK

--

3

Use a test lamp in order to backprobe the sunroof module harness connector C2 terminal B to ground.

Does the test light illuminate?

--

Go to Step 5

Go to Step 4

4

Repair the poor connection or an open in circuit 343 between S 394 and the sunroof module harness connector C2 terminal B.

Has the repair been made and the system rechecked?

--

System OK

--

5

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the sunroof switch.
  3. Turn the ignition switch to the RUN position.
  4. Use a J 39200 in order to measure the voltage by backprobing between B+ and the sunroof switch harness connector terminal D.

Is the voltage within the specified range?

9-14 V

Go to Step 6

Go to Step 7

6

  1. Turn the ignition switch to the LOCK position.
  2. Reconnect the sunroof switch.
  3. Turn the ignition switch to the RUN position.
  4. Use a J 39200 in order to measure the voltage by backprobing between B+ and the sunroof switch harness connector terminal B.

Is the voltage within the specified range?

9-14 V

Go to Step 8

Go to Step 9

7

Use a J 39200 in order to measure the voltage by backprobing between B+ and the sunroof module connector C1 terminal 5.

Is the voltage within the specified range?

9-14 V

Go to Step 10

Go to Step 11

8

  1. Use a J 39200 in order to measure the voltage by backprobing between B+ and the sunroof switch terminal E.
  2. Press the sunroof switch to the CLOSED position.

Is the voltage within the specified range?

9-14 V

Go to Step 12

Go to Step 9

9

Replace the sunroof switch. Refer to Sunroof Switch Replacement in Roof.

Has the repair been made and the system rechecked?

--

System OK

--

10

Repair the poor connection or an open in circuit 128.

Has the repair been made and the system rechecked?

--

System OK

--

11

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the sunroof module connector C2.
  3. Turn the ignition switch to the RUN position.
  4. Use a J 39200 in order to backprobe between B+ and the sunroof module harness connector C2 terminal D.

Is the voltage level acceptable?

Go to Step 13

Go to Step 14

12

Use a J 39200 in order to measure the voltage by backprobing between the sunroof harness connector terminal B and ground.

Is the voltage equal the specified value?

5 V

Go to Step 15

Go to Step 16

13

Replace the sunroof module. Refer to Power Sunroof Express Module Replacement in Roof.

Has the repair been made and the system rechecked?

--

System OK

--

14

Repair the following conditions in circuit 350 between the sunroof module harness connector C2 terminal D and G 302.

Has the repair been made and the system rechecked?

--

System OK

--

15

Use a J 39200 in order to measure the voltage by backprobing between the sunroof switch harness connector terminal E and ground.

Is the voltage equal to the specified value?

5 V

Go to Step 17

Go to Step 18

16

Use a J 39200 in order to measure the voltage by backprobing between the sunroof module harness connector C1 terminal 6 and ground.

Is the voltage equal to the specified value?

5 V

Go to Step 22

Go to Step 21

17

  1. Turn the ignition switch to the LOCK position.
  2. Reconnect the sunroof switch.
  3. Disconnect the sunroof actuator connector C3.
  4. Turn the ignition switch to the RUN position.
  5. Use a J 39200 in order to backprobe between the sunroof actuator harness connector C3 terminal A and terminal B.
  6. Press the sunroof switch to the OPEN position.
  7. Press the sunroof switch to the CLOSE position.

Is the voltage level within the specified range?

9-14 V

Go to Step 19

Go to Step 30

18

Use a J 39200 in order to measure the voltage by backprobing between the sunroof module harness connector C1 terminal 7 and ground.

Is the voltage equal to the specified value?

5 V

Go to Step 20

Go to Step 28

19

Replace the sunroof actuator. Refer to Sunroof Actuator Replacement in Roof.

Has the repair been made and the system rechecked?

--

System OK

--

20

Repair the poor connection or an open in circuit 110.

Has the repair been made and the system rechecked?

--

System OK

--

21

Repair the poor connection or an open in circuit 100.

Has the repair been made and the system rechecked?

--

System OK

--

22

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the sunroof module connector C1.
  3. Turn the ignition switch to the RUN position.
  4. Use a J 39200 in order to measure the voltage by backprobing between B+ and the sunroof module harness connector C1 terminal 6.

Is the voltage level acceptable?

--

Go to Step 23

Go to Step 24

23

Repair the short to ground in circuit 100.

Has the repair been made and the system rechecked?

--

System OK

--

24

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the sunroof module connector C2.
  3. Turn the ignition switch to the RUN position.
  4. Use a J 39200 in order to measure the voltage by backprobing between the sunroof module harness connector C2 terminal B and terminal D.

Is the voltage within the specified range?

9-14 V

Go to Step 13

Go to Step 25

25

Use a J 39200 in order to measure the voltage by backprobing between the sunroof module harness connector C2 terminal B and ground.

Is the voltage within the specified range?

9-14 V

Go to Step 26

Go to Step 27

26

Repair the poor connection or an open in circuit 350 between S 390 and the sunroof module connector C2 terminal D.

Has the repair been made and the system rechecked?

--

System OK

--

27

Repair the poor connection or an open in circuit 343 between S 390 and the sunroof module connector C2 terminal B and S 394.

Has the repair been made and the system rechecked?

--

System OK

--

28

Use a J 39200 in order to measure the voltage by backprobing between B+ and the sunroof module harness connector C1 terminal 7.

Is the voltage within the specified range?

9-14 V

Go to Step 29

Go to Step 24

29

Repair the short to ground in circuit 110.

Has the repair been made and the system rechecked?

--

System OK

--

30

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the sunroof module connector C2.
  3. Use a J 39200 in order to measure the voltage by backprobing between the sunroof actuator connector C3 terminal A and ground.

Does any voltage exist?

--

Go to Step 31

Go to Step 32

31

Repair a short to B+ in circuit 127.

Has the repair been made and the system rechecked?

--

System OK

--

32

Use a J 39200 in order to measure the voltage between B+ and the sunroof actuator harness connector C3 terminal A.

Does any voltage exist?

--

Go to Step 33

Go to Step 34

33

Repair a short to ground in circuit 127.

Has the repair been made and the system rechecked?

--

System OK

--

34

Use a J 39200 in order to inspect the continuity in circuit 127 between the sunroof module harness connector C2 terminal C and the sunroof actuator connector C3 terminal A.

Is there continuity in circuit 127?

--

Go to Step 35

Go to Step 36

35

Use a J 39200 in order to measure the voltage between the sunroof actuator harness connector C3 terminal B and ground.

Does any voltage exist?

--

Go to Step 37

Go to Step 38

36

Repair the poor connection or an open in circuit 127.

Has the repair been made and the system rechecked?

--

System OK

--

37

Repair a short to B+ in circuit 129.

Has the repair been made and the system rechecked?

--

System OK

--

38

Use a J 39200 in order to measure the voltage between B+ and the sunroof actuator harness connector C3 terminal B.

Does any voltage exist?

--

Go to Step 39

Go to Step 40

39

Repair a short to ground in circuit 129.

Has the repair been made and the system rechecked?

--

System OK

--

40

Use a J 39200 in order to inspect the continuity in circuit 129 between the sunroof module harness connector C2 terminal A and the sunroof actuator connector C3 terminal B.

Is there continuity in circuit 129?

--

Go to Step 41

Go to Step 42

41

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the sunroof module connector C1.
  3. Turn the ignition to the RUN position.
  4. Use a J 39200 in order to backprobe between the sunroof module harness connector C1 terminal 8 and ground.

Is the voltage equal to the specified value?

5 V

Go to Step 44

Go to Step 43

42

Repair the poor connection or an open in circuit 129.

Has the repair been made and the system rechecked?

--

System OK

--

43

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the sunroof module connector C1.
  3. Disconnect the sunroof module connector C4.
  4. Use a J 39200 in order to inspect for continuity to ground in the RED wire.

Is there continuity to ground in the RED wire?

--

Go to Step 53

Go to Step 54

44

Use a J 39200 in order to backprobe between the sunroof module harness connector C1 terminal 2 and ground.

Is the voltage equal to the specified value?

5 V

Go to Step 45

Go to Step 13

45

Use a J 39200 in order to backprobe between B+ and the sunroof actuator connector C4 terminal A.

Is the voltage within the specified range?

9-14 V

Go to Step 46

Go to Step 47

46

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the sunroof module connector C1.
  3. Use a J 39200 in order to backprobe between the sunroof module harness connector C1 terminal 2 and ground.

Does any voltage exist?

--

Go to Step 48

Go to Step 49

47

Use a J 39200 in order to backprobe between B+ and the sunroof actuator harness connector C5 terminal C.

Is the voltage within the specified range?

9-14 V

Go to Step 19

Go to Step 50

48

Repair the short to B+ in the YEL wire.

Has the repair been made and the system rechecked?

--

System OK

--

49

Repair the a poor connection or an open in the YEL wire.

Has the repair been made and the system rechecked?

--

System OK

--

50

Use a J 39200 in order to backprobe between B+ and the sunroof actuator harness connector C4 terminal B.

Is the voltage within the specified range?

9-14 V

Go to Step 51

Go to Step 52

51

Repair the a poor connection or an open in the DK BLU wire between S 399 and the sunroof actuator connector C5 terminal C.

Has the repair been made and the system rechecked?

--

System OK

--

52

Use a J 39200 in order to backprobe between B+ and the sunroof module connector C1 terminal 1.

Is the voltage within the specified range?

9-14 V

Go to Step 55

Go to Step 13

53

Repair the short to ground in the RED wire.

Has the repair been made and the system rechecked?

--

System OK

--

54

Repair the following conditions in the DK BLU wire between the sunroof module connector C1 terminal 1 and S 399.

Has the repair been made and the system rechecked?

--

System OK

--

55

  1. Reconnect the sunroof module connector C1.
  2. Turn the ignition switch to the RUN position.
  3. Use a J 39200 in order to measure the voltage between the sunroof actuator connector C4 terminal C and ground.

Is the voltage equal the specified value?

5 V

Go to Step 19

Go to Step 13