GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 1998 🢒 Regal 🢒 Body and Accessories 🢒 Roof 🢒 Power Sunroof Does Not Open

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 switch.
  3. Turn the ignition switch to the RUN position.
  4. Use a J 39200 digital multimeter (DMM) in order to measure the voltage by backprobing between B+ and the sunroof switch harness connector terminal F.

Is the voltage within the specified range?

9-14 V

Go to Step 3

Go to Step 4

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

Is the voltage within the specified range?

9-14 V

Go to Step 5

Go to Step 6

4

Use a J 39200 DMM in order to measure the voltage by backprobing between B+ and the sunroof module harness connector C1 terminal 3 and B+.

Is the voltage within the specified range?

9-14 V

Go to Step 7

Go to Step 8

5
  1. Use a J 39200 DMM in order to measure the voltage by backprobing between B+ and the sunroof switch harness connector terminal B.
  2. Press the sunroof switch to the CLOSED position.

Is the voltage within the specified range?

9-14 V

Go to Step 9

Go to Step 6

6
  1. Replace the sunroof switch. Refer to Sunroof Switch Replacement .
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

7
  1. Repair the following conditions in CKT 128:
    2. • A poor connection
    • An open
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

8
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof module harness connector C2.
  3. Use a J 39200 DMM in order to backprobe between B+ and the sunroof module harness connector C2 terminal D.

Is the voltage within the specified range?

9-14 V

Go to Step 10

Go to Step 11

9

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

Is the voltage equal to the specified value?

5V

Go to Step 12

Go to Step 13

10
  1. Replace the sunroof module. Refer to Sunroof Switch Replacement .
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

11
  1. Repair the following conditions in CKT 850 between the sunroof module harness connector C2 terminal D and G 402:
    2. • A poor connection
    • An open
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

12

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

Is the voltage equal to the specified value?

5V

Go to Step 14

Go to Step 15

13

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

Is the voltage equal to the specified value?

5V

Go to Step 18

Go to Step 19

14
  1. Turn the ignition switch to the OFF position.
  2. Reconnect the sunroof switch.
  3. Disconnect the sunroof actuator harness connector C3.
  4. Turn the ignition switch to the RUN position.
  5. Use a J 39200 DMM in order to backprobe between the sunroof actuator harness connector C3 terminal 1 and terminal 2.
  6. Press the sunroof switch to the OPEN position.
  7. Press the sunroof switch to the CLOSED position.

Is the voltage level within the specified range in both cases?

9-14 V

Go to Step 16

Go to Step 27

15

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

Is the voltage equal to the specified value?

5V

Go to Step 17

Go to Step 25

16
  1. Replace the sunroof actuator. Refer to Sunroof Actuator Replacement .
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

17
  1. Repair the following conditions in CKT 110:
    2. • A poor connection
    • An open
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

18
  1. Repair the following conditions in CKT 100:
    2. • A poor connection
    • An open
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

19
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof module harness connector C1.
  3. Use a J 39200 DMM in order to measure the voltage by backprobing between B+ and the sunroof module harness connector C1 terminal 2.

Is there voltage?

--

Go to Step 20

Go to Step 21

20
  1. Repair the short to ground in CKT 100.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

21
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof module harness connector C2.
  3. Turn the ignition switch to the RUN position.
  4. Use a J 39200 DMM 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 10

Go to Step 22

22

Use a J 39200 DMM 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 23

Go to Step 24

23
  1. Repair the following conditions in CKT 850 between the sunroof module harness connector C2 terminal D and G 402:
    2. • The poor connection
    • The open
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

24
  1. Repair the poor connection or the open in CKT 143.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

25

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

Is the voltage within the specified range?

9-14 V

Go to Step 26

Go to Step 21

26
  1. Repair the short to ground in CKT 110.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

27
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof module connector C2.
  3. Use a J 39200 DMM in order to measure the voltage by backprobing between the sunroof actuator harness connector C3 terminal 1 and ground.

Is voltage detected?

--

Go to Step 28

Go to Step 29

28
  1. Repair the short to B+ in CKT 127.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

29

Use a J 39200 DMM in order to measure the voltage between B+ and the sunroof actuator harness connector C3 terminal 1.

Is voltage detected?

--

Go to Step 30

Go to Step 31

30
  1. Repair the short to ground in CKT 127.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

31

Use a J 39200 DMM in order to inspect for continuity in CKT 127 between the sunroof module harness connector C2 terminal C and the sunroof actuator harness connector C3 terminal 1.

Does continuity occur in CKT 127?

--

Go to Step 32

Go to Step 33

32

Use a J 39200 DMM in order to measure the voltage between the sunroof actuator harness connector C2 terminal 2 and ground.

Is there voltage?

--

Go to Step 34

Go to Step 35

33
  1. Repair the following conditions in CKT 127:
    2. • The poor connection
    • The open
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

34
  1. Repair a short to B+ in CKT 129.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

35

Use a J 39200 DMM in order to measure the voltage between B+ and the sunroof actuator harness connector C3 terminal 2.

Is voltage detected?

--

Go to Step 36

Go to Step 37

36
  1. Repair the short to ground in CKT 129
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

37

Use a J 39200 DMM in order to inspect for continuity in CKT 129 between the sunroof module harness connector C2 terminal A and the sunroof actuator harness connector C3 terminal 2.

Is voltage detected?

--

Go to Step 38

Go to Step 39

38
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof module harness connector C2.
  3. Turn the ignition switch to the RUN position.
  4. Use a J 39200 DMM in order to backprobe between the sunroof module harness connector C1 terminal 8 and ground.

Is the voltage equal to the specified value?

5V

Go to Step 40

Go to Step 41

39
  1. Repair the following conditions in CKT 129:
    2. • The poor connection
    • The open
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

40

Use a J 39200 DMM in order to backprobe between the B+ and the limit switch module harness connector C4 terminal 3.

Is the voltage within the specified range?

9-14V

Go to Step 42

Go to Step 43

41

Use a J 39200 DMM in order to backprobe between the sunroof module harness connector C1 terminal 7 and ground.

Is the voltage equal to the specified value?

5 V

Go to Step 44

Go to Step 45

42
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof module harness connector C1.
  3. Use a J 39200 DMM in order to backprobe between the sunroof module harness connector C1 terminal 8 and ground.

Is voltage detected?

--

Go to Step 46

Go to Step 47

43

Use a J 39200 DMM in order to backprobe between the B+ and the sunroof module harness connector C4 terminal 2.

Is the voltage equal to the specified value?

B+

Go to Step 48

Go to Step 49

44

Use a J 39200 DMM in order to backprobe between the sunroof module harness connector C1 terminal 6 and ground.

Is the voltage equal to the specified value?

5V

Go to Step 50

Go to Step 10

45
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof module harness connector C1.
  3. Disconnect the limit switch module connector C4.
  4. Use a J 39200 DMM in order to inspect for continuity to ground in the RED wire.

Is continuity to ground present in the RED wire?

--

Go to Step 51

Go to Step 54

46
  1. Repair a short to B+ in the WHT wire.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

47
  1. Repair the following conditions in the WHT wire:
    2. • The poor connection
    • The open
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

48
  1. Replace the limit switch module.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

49

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

Is the voltage within the specified range?

9-14 V

Go to Step 52

Go to Step 10

50
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof module harness connector C1.
  3. Disconnect the limit switch module connector C4.
  4. Use a J 39200 DMM in order to inspect for continuity to ground in the BLK wire.

Is continuity to ground detected in the BLK wire?

--

Go to Step 53

Go to Step 54

51
  1. Repair the short to ground in the RED wire.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

52
  1. Repair the following conditions in the BLK/WHT wire:
    2. • The poor connection
    • The open
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

53
  1. Repair the short to ground in the BLK wire.
  2. Inspect the system.

Is the repair complete?

--

Go to Power Sunroof System Check

--

54
  1. Reconnect the sunroof module harness connector C1.
  2. Turn the ignition switch to the RUN position.
  3. Use a J 39200 DMM in order to measure the voltage between the limit switch module harness connector C4 terminal 1 and ground.

Is the voltage same as the specified value?

5V

Go to Step 48

Go to Step 10