GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 Regal 🢒 Body and Accessories 🢒 Roof 🢒 Power Sunroof Inoperative

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 to the ON position.
  2. Operate the LF door power window.

Does the LF door power window operate?

--

Go to Step 3

Go to Step 6

3
  1. Remove the sunroof switch from the headliner and leave the sunroof switch harness connector connected.
  2. Using a Digital Multi Meter (DMM ) measure the voltage by backprobing between the sunroof switch connector terminal B and ground.

Is the voltage measured within the specified range?

4.5-5.5 V

Go to Step 4

Go to Step 19

4

Using a (DMM) measure the voltage by backprobing between the sunroof switch harness connector terminal C and ground.

Is the voltage measured within the specified range?

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

4.5-5.5 V

Go to Step 5

Go to Step 23

5

Using a (DMM) measure the voltage by backprobing between the sunroof switch harness connector terminals B and F.

Is the voltage measured within the specified range?

4.5-5.5 V

Go to Step 10

Go to Step 26

6

Check the PWR WINDOWS PWR SUNROOF circuit breaker located in the fuse block.

Is the PWR WINDOWS PWR SUNROOF circuit breaker open?

--

Go to Step 7

Go to Step 8

7

Repair short to ground in circuit 143.

Has the repair been Completed ?

--

Go to Step 44

--

8

Using a test light, backprobe between C398 terminal A and ground.

Does the test light illuminate?

--

Go to Step 9

Go to Step 28

9
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof module electrical connector C2.
  3. Turn the ignition switch to the ON position.
  4. Using a test light connect between the sunroof module harness connector C2 terminals B and D.

Does the test light illuminate?

--

Go to Step 3

Go to Step 29

10
  1. Using a test light, backprobe between the sunroof module harness connector C2 terminal A and ground.
  2. While observing the test light, press and hold close on the sunroof switch.

Does the test light illuminate?

--

Go to Step 11

Go to Step 22

11
  1. Using a test light, backprobe between the sunroof module harness connector C2 terminal C and ground.
  2. While observing the test light, press and hold open on the sunroof switch.

Does the test light illuminate?

--

Go to Step 14

Go to Step 22

12
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof actuator connector C3.
  3. Connect a test light between the sunroof actuator harness connector C3 terminals 1 and 2.
  4. While observing the test light, press and hold close on the sunroof switch.

Does the test light illuminate?

--

Go to Step 13

Go to Step 30

13
  1. Leave the test light connected (from previous step).
  2. While observing the test light, press and hold open on the sunroof switch.

Does the test light illuminate?

--

Go to Step 18

Go to Step 30

14
  1. Turn the ignition switch to the OFF position.
  2. Reconnect the sunroof module.
  3. Turn the ignition switch to the ON position.
  4. Using a J 39200, measure the voltage by backprobing between the limit switch module harness connector C4 terminal 1 and ground.

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

4.5-5.5 V

Go to Step 15

Go to Step 31

15

Using a J 39200, measure the voltage by backprobing between the limit switch module harness connector C4 terminal 3 and ground.

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

4.5-5.5 V

Go to Step 16

Go to Step 33

16

Using a J 39200, measure the voltage by backprobing between the limit switch module harness connector C4 terminal 4 and ground.

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

4.5-5.5 V

Go to Step 17

Go to Step 35

17

Using a J 39200, measure the voltage by backprobing between the limit switch module harness connector C4 terminals 2 and 4.

Is the voltage measured within the specified range?

4.5-5.5 V

Go to Step 12

Go to Step 37

18

Replace the sunroof actuator. Refer to Sunroof Actuator Replacement Power Sunroof Motor Replacement for service procedure.

Has the repair been Completed ?

--

Go to Step 44

--

19
  1. Disconnect the sunroof switch electrical connector.
  2. Using a J 39200 and a J 35616 A kit, measure the voltage between the sunroof switch harness connector terminal B and ground.

Is the voltage measured within the specified range?

4.5-5.5 V

Go to Step 21

Go to Step 20

20

Check for an open or short to ground in circuit 100.

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

--

Go to Step 39

Go to Step 22

21

Replace the sunroof switch. Refer to Sunroof Switch Replacement Power Sunroof Switch Replacement for service procedure.

Has the repair been completed ?

--

Go to Step 44

--

22

Replace the sunroof module. Refer to Power Sunroof Module Replacement for service procedure.

Has the repair been completed ?

--

Go to Step 44

--

23
  1. Disconnect the sunroof switch electrical connector.
  2. Using a J 39200 and a J 35616 A kit, measure the voltage between the sunroof switch harness connector terminal C and ground.

Is the measured voltage within the specified value?

4.5-5.5 V

Go to Step 21

Go to Step 24

24

Repair the open or short to ground in circuit 110.

Has the repair becompleted ?

--

Go to Step 44

--

25

Repair the open or short to ground.

Has the repair been completed ?

--

Go to Step 44

--

26
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the sunroof switch electrical connector.
  3. Disconnect the sunroof module electrical connector C1.
  4. Using a (DMM) measure the resistance between the sunroof switch harness connector terminal F and the sunroof module harness connector C1 terminal 3.

Is the measured resistance within the specified range?

Less than 2 ohms

Go to Step 22

Go to Step 27

27

Repair the poor connection or an open in circuit 128.

Has the repair been completed ?

--

Go to Step 44

--

28

Repair the poor connection or an open in circuit 143.

Has the repair been completed ?

--

Go to Step 44

--

29

Repair the poor connection or open in circuit 850.

Has the repair been completed ?

--

Go to Step 44

--

30

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

Has the repair been completed ?

--

Go to Step 44

--

31
  1. Disconnect the limit switch module electrical connector C4.
  2. Using a (DMM) measure the voltage between the limit switch module harness connector C4 terminal 1 and ground.

Is the voltage measured within the specified range?

4.5-5.5 V

Go to Step 33

Go to Step 32

32

Locate open or short to ground in the BLK wire between the sunroof module harness connector C1 terminal 6 and the limit switch module harness connector C4 terminal 1.

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

--

Go to Step 40

Go to Step 22

33
  1. Disconnect the limit switch module harness connector C4.
  2. Using a (DMM) measure the voltage between the limit switch module harness connector C4 terminal 3 and ground.

Is the voltage measured within the specified range?

4.5-5.5 V

Go to Step 22

Go to Step 34

34

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 3.

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

--

Go to Step 41

Go to Step 22

35
  1. Disconnect the limit switch module harness connector C4.
  2. Using a J 39200 and a J 35616 A kit, measure the voltage between the limit switch module harness connector C4 terminal 4 and ground.

Is the voltage measured within the specified range?

5.5-6.5 V

Go to Step 22

Go to Step 36

36

Locate open or short to ground in the RED wire between the sunroof module harness connector C1 terminal 7 and the limit switch module harness connector C4 terminal 4.

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

--

Go to Step 42

Go to Step 22

37

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 2.

Is there an open in the BLK/WHT wire?

--

Go to Step 43

Go to Step 22

38

Repair the short to B+.

Has the repair been completed ?

--

Go to Step 44

--

39

Repair the open or short to ground in circuit 100.

Has the repair been completed ?

--

Go to Step 44

--

40

Repair open or short to ground in the BLK wire between the sunroof module harness connector C1 terminal 6 and the limit switch module harness connector C4 terminal 1.

Has the repair been completed ?

--

Go to Step 44

--

41

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 3.

Has the repair been completed?

--

Go to Step 44

--

42

Repair open or short to ground in the RED wire between the sunroof module harness connector C1 terminal 7 and the limit switch module harness connector C4 terminal 4.

Has the repair been completed ?

--

Go to Step 44

--

43

Repair the open in the BLK/WHT wire between the sunroof module harness connector C1 terminal 1 and the limit switch module harness connector C4 terminal 2.

Has the repair been completed ?

--

Go to Step 44

--

44

Verify that the system operates properly .

Does the system operate properly ?

--

System OK

Go to Power Sunroof System Check