GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 LeSabre 🢒 Body and Accessories 🢒 Roof 🢒 Power Sunroof Does Not Close

Diagnostic Aids

Refer to Testing for Electrical Intermittents and Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The steps below refer to the test steps in the diagnostic table.

  1. The vent-to-seal, is a timing program inside of the module that is triggered by the power sunroof motor limit switch. After the front of the glass makes contact with the roof, the rear of the glass should raise slightly then seat.

  1. Test step commands the sunroof control module to close.

  1. This step tests the battery positive voltage feed circuit for a short.

  1. This step tests the power sunroof circuitry up to the motor assembly.

Power Sunroof Does Not Close

Step

Action

Value(s)

Yes

No

SCHEMATIC REFERENCE: Sunroof Schematics

1

Did you perform A Diagnostic System Check - Power Sunroof?

--

Go to Step 2

Go to Diagnostic System Check - Power Sunroof

2
  1. Turn ON the ignition, with the engine OFF.
  2. Press the power sunroof switch to the close position.

Does the sunroof close flush, from the vent to seal position?

--

Go to Diagnostic Aids

Go to Step 3

3

Test the 20 amp RAP fuse in the Rear Fuse Block.

Was the fuse blown?

--

Go to Step 11

Go to Step 4

4

Did the Power Sunroof close but not seat properly?

--

Go to Step 5

Go to Step 8

5
  1. Disconnect the Power Sunroof Motor limit switch connector.
  2. Measure the limit switch input voltage to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 6

Go to Step 7

6

Measure the voltage across the limit switch harness connector.

Is the voltage within the specified range?

10-15 V

Go to Step 27

Go to Step 23

7

Measure the resistance of the Power Sunroof Motor limit switch input circuit?

Is the resistance within the specified range?

1-3 ohms

Go to Step 27

Go to Step 24

8

  1. Turn OFF the ignition.
  2. Disconnect the overhead console switch wiring harness.
  3. Turn ON the ignition.
  4. Using 3 amp fused jumper wires, jumper the slide and vent circuits simultaneously to the ground circuit of the overhead console switch harness connector.

Does the sunroof close?

--

Go to Step 9

Go to Step 13

9

Test for poor connection/terminal tension at the overhead console switch harness connector.

Did you find and correct the condition?

--

Go to Step 31

Go to Step 10

10

Replace the overhead console switch. Refer to Sunroof Switch Replacement .

Did you complete the replacement?

--

Go to Step 31

--

11

  1. Turn OFF the ignition.
  2. Open the drivers door.
  3. Disconnect the 4-way harness connector at the power sunroof control module.
  4. Measure the resistance from the power sunroof control module harness connector battery positive voltage terminal to ground.

Is the resistance equal to the specified value?

OL

Go to Symptoms in Retained Accessory Power

Go to Step 12

12

Repair short to ground in the power sunroof control module battery positive circuit.

Did you find and correct the condition?

--

Go to Step 31

--

13
  1. Turn OFF the ignition.
  2. Disconnect the power sunroof control module 8-way harness connector.
  3. Measure the resistance between the slide open terminal of the overhead console switch and the slide open terminal of the Power Sunroof Control Module harness connector.

Is the resistance within the specified range?

1-3 ohms

Go to Step 15

Go to Step 14

14

Repair open circuit between the overhead console switch and the power sunroof control module.

Did you find and correct the condition?

--

Go to Step 31

--

15

Measure the resistance between the vent open terminal of the overhead console switch harness connector and the vent open terminal of the Power Sunroof Control Module harness connector.

Is the resistance within the specified range?

1-3 ohms

Go to Step 17

Go to Step 16

16

Repair open circuit between the overhead console switch and the power sunroof control module.

Did you find and correct the condition?

--

Go to Step 31

--

17

Measure the resistance between the ground terminal of the overhead console switch harness connector and the ground terminal of the Power Sunroof Control Module harness connector.

Is the resistance within the specified range?

1-3 ohms

Go to Step 19

Go to Step 18

18

Repair open circuit between the overhead console switch and the power sunroof control module.

Did you find and correct the condition?

--

Go to Step 31

--

19
  1. Disconnect the 4-way power sunroof control module harness connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage from the battery positive voltage terminal to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 21

Go to Step 20

20

Repair open circuit in the power sunroof control module battery positive circuit.

Did you find and correct the condition?

--

Go to Step 31

--

21

Measure the voltage between the Power sunroof Control Module 4-wire harness connector battery positive voltage and ground terminal .

Is the voltage within the specified range?

10-15 V

Go to Step 25

Go to Step 22

22

Repair open circuit in the power sunroof control module ground circuit.

Did you find and correct the condition?

--

Go to Step 31

--

23

Repair open circuit in the Power Sunroof Motor limit switch ground circuit.

Did you find and correct the condition?

--

Go to Step 31

Go to Step 28

24

Repair open circuit in the Power Sunroof Motor limit switch input circuit.

Did you find and correct the condition?

--

Go to Step 31

--

25

  1. Turn Off the ignition.
  2. Reconnect the overhead console switch.
  3. Reconnect the 4-wire power sunroof control module harness connector.
  4. Reconnect the 8-way power sunroof control module harness connector.
  5. Disconnect the power sunroof motor assembly harness connector.
  6. Turn ON the ignition, with the engine OFF.
  7. Measure the voltage across the motor control terminals while operating the overhead console switch to the closed position.

Ignoring polarity, is the voltage within the specified range?

10-15 V

Go to Step 27

Go to Step 26

26

Test for an open in the 2-wire Power Sunroof Motor Circuit.

Did you find and correct the condition?

--

Go to Step 31

Go to Step 28

27

Test for poor connections/ terminal tension at the power sunroof motor assembly harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 29

28

Test for poor connections/ terminal tension at the Power Sunroof Module harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 31

Go to Step 30

29

Important: Inspect the power sunroof assembly for binding or mechanical failure.

Replace the power sunroof motor assembly. Refer to Power Sunroof Motor Replacement .

Did you complete the replacement?

--

Go to Step 31

--

30

Replace the power sunroof control module. Refer to Power Sunroof Express Module Replacement .

Did you complete the replacement?

--

Go to Step 31

--

31

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2