GM Service Manual Online
For 1990-2009 cars only

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Action

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Schematic Reference: Sunroof Schematics

Connector End View Reference: Sunroof Connector End Views

1

Did you review the Sunroof System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Roof

2

Attempt to operate the sunroof to the full open then closed positions.

Does the sunroof system operate normal?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Does the sunroof motor make a brief movement when the switch is activated in either direction?

Go to Step 11

Go to Step 4

4

  1. Disconnect the sunroof motor connector.
  2. Connect a test lamp between the motor control circuit terminals in the harness connector.
  3. Operate the sunroof switch in both directions.

Does the test lamp illuminate when the switch is operated in both directions?

Go to Step 25

Go to Step 5

5

  1. Disconnect the sunroof module connector C2.
  2. Connect a test lamp from the open switch signal circuit terminal in the harness connector to a good ground.
  3. Turn the ignition ON.
  4. Press the sunroof open switch.

Does the test lamp illuminate?

Go to Step 6

Go to Step 7

6

  1. Connect a test lamp from the close switch signal circuit terminal in the harness connector to a good ground.
  2. Press the sunroof close switch.

Does the test lamp illuminate?

Go to Step 8

Go to Step 14

7

  1. Disconnect the sunroof switch connector.
  2. Connect a test lamp from the retained accessory power (RAP) circuit terminal in the harness connector to a good ground.
  3. Turn the ignition ON.

Does the test lamp illuminate?

Go to Step 15

Go to Step 16

8

  1. Disconnect the sunroof module connector C1.
  2. Connect a test lamp from the battery voltage supply circuit terminal in the harness connector to a good ground.

Does the test lamp illuminate?

Go to Step 9

Go to Step 21

9

Connect a test lamp from the battery voltage supply circuit terminal to the ground circuit terminal in the harness connector.

Does the test lamp illuminate?

Go to Step 10

Go to Step 22

10

  1. Connect a test lamp from the RAP circuit terminal in the C2 harness connector to ground.
  2. Turn the ignition on.

Does the test lamp illuminate?

Go to Step 17

Go to Step 23

11

  1. Disconnect the sunroof motor connector.
  2. Using a DMM measure the voltage from the hall effect sensor 1 signal circuit terminal in the harness connector to a good ground.
  3. Turn the ignition ON.

Does the DMM display approximately battery voltage?

Go to Step 12

Go to Step 18

12

Using a DMM measure the voltage from the hall effect sensor 2 signal circuit terminal in the harness connector to a good ground.

Does the DMM display approximately battery voltage?

Go to Step 13

Go to Step 19

13

Using a DMM measure the voltage from the hall effect sensor 2 signal circuit terminal to the low reference circuit terminal in the harness connector.

Does the DMM display approximately battery voltage?

Go to Step 25

Go to Step 20

14

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

Did you find and correct the condition?

Go to Step 30

Go to Step 24

15

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

Did you find and correct the condition?

Go to Step 30

Go to Step 24

16

Test the RAP supply circuit to the sunroof switch for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Retained Accessory Power (RAP) Inoperative

17

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

Did you find and correct the condition?

Go to Step 30

Go to Step 26

18

Test the hall effect sensor 1 signal circuit for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 26

19

Test the hall effect sensor 2 signal circuit for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 26

20

Test the hall effect sensor low reference circuit for an open of high resistance. Refer to Circuit Testing and to Wiring Repairs .

Did you find and correct the condition?

Go to Step 30

Go to Step 26

21

Repair the battery voltage supply circuit to the sunroof control module for an open or short to ground. Refer to Circuit Testing and to Wiring Repairs .

Is the repair complete?

Go to Step 30

--

22

Repair the sunroof control module ground circuit for an open or high resistance. Refer to Circuit Testing and to Wiring Repairs .

Is the repair complete?

Go to Step 30

--

23

Repair the RAP supply circuit to the sunroof control module for an open or high resistance. Refer to Circuit Testing and to Wiring Repairs .

Is the repair complete?

Go to Step 30

--

24

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

Did you find and correct the condition?

Go to Step 30

Go to Step 27

25

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

Did you find and correct the condition?

Go to Step 30

Go to Step 28

26

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

Did you find and correct the condition?

Go to Step 30

Go to Step 29

27

Replace the sunroof switch. Refer to Sunroof Switch Replacement .

Is the repair complete?

Go to Step 30

--

28

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

Is the repair complete?

Go to Step 30

--

29

Replace the sunroof control module. Refer to Sunroof Control Module Replacement .

Is the repair complete?

Go to Step 30

--

30

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2