GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

    • The sunroof motor and sunroof control module are integral parts of the sunroof motor/actuator assembly and are not serviced separately.
    • If voltage is not measured on the sunroof switch open signal or sunroof switch close signal circuits, the fault could be in the accessory voltage circuit, battery positive voltage circuit, or sunroof motor/actuator ground circuit. If the sunroof motor/actuator is not being powered, neither will the sunroof switch signal circuits.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step is used to determine the correct diagnostic path. The path depends on if the sunroof is inoperative and in the open position, or if the sunroof is inoperative and in the closed position.

  2. This step tests the sunroof switch open switch.

  3. This step tests the sunroof switch close switch.

Step

Action

Values

Yes

No

Schematic Reference: Sunroof Schematics

Connector End View Reference: Sunroof Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Attempt to operate the sunroof through its full range of functions in order to verify that the power sunroof inoperative fault is present.

Does the power sunroof system operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Perform the sunroof re-initialization. Refer to Sunroof Motor/Actuator Initialization/Teach Process .

Does the sunroof operate normally?

--

Go to Step 25

Go to Step 4

4

Is the sunroof in the fully closed position?

--

Go to Step 5

Go to Step 8

5

  1. Disconnect the sunroof switch.
  2. Turn ON the ignition, with the engine OFF.
  3. Connect a 3-amp fused jumper wire to the low reference circuit of the sunroof switch harness connector.
  4. Connect the other end of the 3-amp fused jumper wire to the sunroof switch open signal circuit of the sunroof switch harness connector, for 3 seconds.

Did the sunroof open?

--

Go to Step 18

Go to Step 6

6

  1. Disconnect the 3-amp fused jumper wire.
  2. Measure the voltage from the sunroof switch open signal circuit of the sunroof switch harness connector to the low reference circuit of the sunroof switch harness connector.

Does the voltage measure near the specified value?

5 V

Go to Step 14

Go to Step 7

7

Measure the voltage from the sunroof switch open signal circuit of the sunroof switch harness connector to a good ground.

Does the voltage measure near the specified value?

5 V

Go to Step 15

Go to Step 11

8

  1. Disconnect the sunroof switch.
  2. Turn ON the ignition, with the engine OFF.
  3. Connect a 3-amp fused jumper wire to the low reference circuit of the sunroof switch harness connector.
  4. Connect the other end of the 3-amp fused jumper wire to the sunroof switch close signal circuit of the sunroof switch harness connector, for 3 seconds.

Did the sunroof close?

--

Go to Step 18

Go to Step 9

9

  1. Disconnect the 3-amp fused jumper wire.
  2. Measure the voltage from the sunroof switch close signal circuit of the sunroof switch harness connector to the low reference circuit of the sunroof switch harness connector.

Does the voltage measure near the specified value?

5 V

Go to Step 16

Go to Step 10

10

Measure the voltage from the sunroof switch close signal circuit of the sunroof switch harness connector to a good ground.

Does the voltage measure near the specified value?

5 V

Go to Step 15

Go to Step 11

11

  1. Disconnect the sunroof motor/actuator harness connector.
  2. Measure the voltage from the battery positive voltage circuit of the sunroof motor/actuator harness connector to a good ground.

Does the voltage measure near the specified value?

B+

Go to Step 12

Go to Step 20

12

Measure the voltage from the accessory voltage circuit of the sunroof motor/actuator harness connector to a good ground.

Does the voltage measure near the specified value?

B+

Go to Step 13

Go to Step 21

13

  1. Turn OFF the ignition.
  2. Measure the resistance from the ground circuit of the sunroof motor/actuator harness connector to a good ground.

Does the resistance measure less than or equal to the specified value?

5 ohms

Go to Step 17

Go to Step 22

14

Test the sunroof switch close signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 25

Go to Step 19

15

Test the sunroof switch low reference circuit for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 25

Go to Step 19

16

Test the sunroof switch open signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 25

Go to Step 19

17

Test the appropriate sunroof switch signal circuit for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 25

Go to Step 19

18

Inspect for poor connections at the harness connector of the sunroof switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 25

Go to Step 23

19

Inspect for poor connections at the harness connectors of the sunroof motor/actuator assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 25

Go to Step 24

20

Repair the short to ground or open in the battery positive voltage circuit of the sunroof motor/actuator assembly. Refer to Wiring Repairs and Connector Repairs .

Did you complete the repair?

--

Go to Step 25

--

21

Repair the short to ground or open in the accessory voltage circuit of the sunroof motor/actuator assembly. Refer to Wiring Repairs and Connector Repairs .

Did you complete the repair?

--

Go to Step 25

--

22

Repair the open in the ground circuit of the sunroof motor/actuator assembly. Refer to Wiring Repairs and Connector Repairs .

Did you complete the repair?

--

Go to Step 25

--

23

Replace the sunroof switch. Refer to Sunroof Switch Replacement .

Did you complete the replacement?

--

Go to Step 25

--

24

Replace the sunroof motor/actuator assembly. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 25

--

25

Operate the system in order to verify the repair.

Did you find and correct the condition?

--

System OK

Go to Step 2