GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Inspect fuses F17 and E12.

Is either fuse open?

--

Go to Step 2

Go to Step 3

2

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

Is the repair complete?

--

System OK

--

3

  1. Turn the ignition ON.
  2. Measure the voltages at fuses F17 and E12.

Are both voltages equal to the specified value?

11-14 V

Go to Step 5

Go to Step 4

4

Repair the power supply to the fuse which did not indicate battery voltage with the ignition ON.

Is the repair complete?

--

System OK

--

5

  1. Disconnect the interior courtesy lamp/power sunroof control switch connector.
  2. Turn the ignition ON.
  3. Test the voltage at terminal 3 of the interior courtesy lamp/power sunroof control switch connector.

Is the voltage equal to the specified value?

11-14 V

Go to Step 7

Go to Step 6

6

Repair the open circuit between fuse F17 and the interior courtesy lamp/power sunroof control switch connector.

Is the repair complete?

--

System OK

--

7

  1. Reconnect the interior courtesy lamp/power sunroof control switch connector.
  2. With the sunroof switch in the OPEN position, measure the voltage at terminal 1 of the interior courtesy lamp/power sunroof control switch connector.
  3. With the sunroof switch in the CLOSE position, measure the voltage at terminal 2 of the interior courtesy lamp/power sunroof control switch connector.

Do both voltages equal the specified value?

11-14 V

Go to Step 9

Go to Step 8

8

Replace the interior courtesy lamp/power sunroof control switch.

Is the repair complete?

--

System OK

--

9

  1. Disconnect the 6-pin sunroof module connector.
  2. With the sunroof switch in the OPEN position, measure the voltage at terminal 4 of the sunroof module connector.
  3. With the sunroof switch in the CLOSE position, measure the voltage at terminal 6 of the sunroof module connector.

Are the voltages equal to the specified value?

11-14 V

Go to Step 11

Go to Step 10

10

Repair the open circuit between the interior courtesy lamp/power sunroof control switch and the sunroof module connector.

Is the repair complete?

--

System OK

--

11

  1. Reconnect the sunroof module.
  2. Remove the sunroof motor, but leave the connectors attached.
  3. Turn the ignition ON.
  4. Use the sunroof switch to attempt to operate the motor in both directions.

Does the motor operate?

--

Go to Step 12

Go to Step 13

12

Repair the jammed sunroof mechanism.

Is the repair complete?

--

System OK

--

13

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

Does the voltmeter indicate the specified voltage when the switch is in either the OPEN or the CLOSE position, one of the switch positions should show reverse polarity?

11-14 V

Go to Step 15

Go to Step 14

14

Replace the sunroof module.

Is the repair complete?

--

System OK

--

15

Replace the sunroof motor.

Does the sunroof operate with the new motor?

--

System OK

Go to Step 14