GM Service Manual Online
For 1990-2009 cars only

Test Description

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

  1. This step tests the sunroof switch low reference circuit for an open.

  2. This step tests the sunroof switch data 6 circuit for a short to ground.

  3. This step tests the sunroof motor control circuits for a short to ground or an open.

Step

Action

Values

Yes

No

Schematic Reference: Sunroof Schematics .

Connector End View Reference: Component 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 power sunroof through its full range of functions in order to verify that the power sunroof inoperative fault is present.

Does the power sunroof operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Inspect the RAP fuse for an open.

Is the fuse open?

--

Go to Step 11

Go to 4Step 4

4

  1. Turn OFF the ignition.
  2. Open the driver door.
  3. Disconnect the sunroof switch.
  4. Measure the resistance from the low reference circuit of the sunroof switch harness connector to a good ground.

Does the resistance measure less than the specified value?

5 Ω

Go to Step 5

Go to Step 12

5

  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage from the sunroof switch data 6 circuit of the sunroof switch harness connector to the sunroof switch low reference circuit of the sunroof switch harness connector.

Does the voltage measure within the specified range?

9-16 V

Go to Step 9

Go to Step 6

6

Test the sunroof switch data 6 circuit of the sunroof switch for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 22

Go to Step 7

7

  1. Turn OFF the ignition.
  2. Open the driver door.
  3. Connect the sunroof switch.
  4. Disconnect the sunroof control module harness connector C1.
  5. Turn ON the ignition, with the engine OFF.
  6. Measure the voltage from the retained accessory power (RAP) relay switch supply voltage circuit of the sunroof control module harness connector C1 to a good ground.

Does the voltage measure within the specified range?

9-16 V

Go to Step 8

Go to Step 13

8

Measure the voltage from the RAP relay switch supply voltage circuit of the sunroof control module harness connector C1 to the ground circuit of the sunroof control module harness connector C1.

Does the voltage measure within the specified range?

9-16 V

Go to Step 15

Go to Step 18

9

Test the sunroof switch. Refer to Power Sunroof Switch Test .

Is the sunroof switch OK?

--

Go to Step 10

Go to Step 16

10

  1. Turn OFF the ignition.
  2. Open the driver door.
  3. Connect the sunroof switch.
  4. Disconnect the sunroof motor.
  5. Turn ON the ignition, with the engine OFF.
  6. Connect a test lamp between the sunroof motor open control circuit of the sunroof motor harness connector and the sunroof motor close control circuit of the sunroof motor harness connector.
  7. Activate the sunroof switch to an open position.
  8. Activate the sunroof switch to a close position.

Does the test lamp illuminate when activated to the open and close positions?

--

Go to Step 17

Go to Step 14

11

Test the RAP relay switch supply voltage circuit of the sunroof control module for a short ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 22

Go to Step 15

12

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

Did you find and correct the condition?

--

Go to Step 22

Go to Step 15

13

Test the RAP relay switch supply voltage circuit of the sunroof control module for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 22

Go to Retained Accessory Power (RAP) Description and Operation

14

Test the sunroof motor control circuits of the sunroof motor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 22

Go to Step 15

15

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

Did you find and correct the condition?

--

Go to Step 22

Go to Step 19

16

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 22

Go to Step 20

17

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

Did you find and correct the condition?

--

Go to Step 22

Go to Step 21

18

Repair the open in the sunroof module ground circuit. Refer to Wiring Repairs and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 22

--

19

Replace the sunroof control module. Refer to Control Module References , for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 22

--

20

Replace the sunroof switch. Refer to Sunroof Switch Replacement .

Did you correct the condition?

--

Go to Step 22

--

21

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

Replace the sunroof motor. Refer to Sunroof Motor/Actuator Replacement .

Did you complete the replacement?

--

Go to Step 22

--

22

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2