GM Service Manual Online
For 1990-2009 cars only

Test Description

The number below refers to the step number on the diagnostic table.

  1. The terminals are not marked on the relay socket, but the terminals are marked on the underside of the relay.

Power Sunroof Inoperative

Step

Action

Values

Yes

No

1

Inspect fuses F15, EF11 and EF29.

Is any fuse open?

--

Go to Step 2

Go to Step 3

2

  1. Check for a short circuit and repair it, if necessary.
  2. Replace the fuses, as necessary.

Is the repair complete?

--

System OK

--

3

  1. Turn the ignition ON.
  2. At the lamp/sunroof switch, measure the voltage at terminal 6 of the switch connector.

Does the voltmeter indicate the specified range?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the open circuit between fuse F15 and the sunroof switch.

Is the repair complete?

--

System OK

--

5

  1. Turn the ignition ON.
  2. With the sunroof switch connected, turn the switch to the closed position.
  3. Measure the voltage at terminal 5 of the switch connector.
  4. With the sunroof switch connected, turn the switch to the open position.
  5. Measure the voltage at terminal 4 of the switch connector.

Are both voltages within the specified range?

11-14 V

Go to Step 7

Go to Step 6

6

Replace the sunroof switch. Refer to Sunroof Switch Replacement .

Is the repair complete?

--

System OK

--

7

  1. Disconnect the sunroof module 6-pin electrical connector.
  2. Use an ohmmeter to measure the resistance between terminal 2 and ground.

Is the resistance equal to the specified value?

0 ohms

Go to Step 9

Go to Step 8

8

Repair the open circuit between ground and terminal 2 of the sunroof module connector.

Is the repair complete?

--

System OK

--

9

  1. With the sunroof module still disconnected, turn the ignition ON.
  2. Measure the voltage at terminal 6 of the connector for the sunroof module.

Does the voltage measure within the specified range?

11-14 V

Go to Step 11

Go to Step 10

10

Repair the open circuit between fuse F15 and terminal 3 of the sunroof module.

Is the repair complete?

--

System OK

--

11

  1. With the sunroof module still disconnected, turn the ignition ON.
  2. Measure the voltage at terminal 6 of the sunroof module with the sunroof switch in the CLOSE position.

Does the voltage measure within the specified range?

11-14 V

Go to Step 13

Go to Step 12

12

Repair the open circuit between the sunroof switch and the sunroof module.

Is the repair complete?

--

System OK

--

13

  1. With the sunroof module still disconnected, turn the ignition ON.
  2. Measure the voltage at terminal 5 of the sunroof module with the sunroof switch in the OPEN position. Does the voltmeter indicate

Does the voltage measure within the specified range?

11-14 V

Go to Step 14

Go to Step 12

14

  1. Reconnect the sunroof module.
  2. Remove the sunroof motor, but leave the connectors attached.
  3. Attempt to operate the motor in both directions by using the sunroof switch.

Does the motor operate?

--

Go to Step 15

Go to Step 16

15

Repair the jammed sunroof mechanism.

Is the repair complete?

--

System OK

--

16

  1. Disconnect both of the one-wire connectors at the sunroof motor.
  2. Connect a voltmeter between the 2 one-wire connectors.
  3. Turn the ignition ON.
  4. Turn the sunroof switch to the CLOSE position and observe the voltmeter reading.
  5. Turn the sunroof switch to the OPEN position and observe the voltmeter reading.

Does the voltage measure within the specified range when the switch is in each position, OPEN or CLOSE?

11-14 V

Go to Step 18

Go to Step 17

17

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

Is the repair complete?

--

System OK

--

18

Replace the sunroof motor. Refer to Sunroof Module Assembly Replacement .

Is the repair complete?

--

System OK

--