GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: Sunroof Schematics

Connector End View Reference: Power Roof Systems Connector End Views

1

Did you perform the Power Sunroof Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Power Sunroof

2

Operate the power sunroof.

Does the system operate normally?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Disconnect the sunroof switch from the harness connector.

Is the sunroof glass in the fully closed position?

--

Go to Step 4

Go to Step 5

4

  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to slide the sunroof glass towards the open position, by connecting a jumper wire between the sunroof switch low reference circuit and the sunroof switch open signal circuit of the sunroof switch harness connector, for 3 seconds.

Did the sunroof glass slide open?

--

Go to Step 28

Go to Step 6

5

  1. Turn ON the ignition, with the engine OFF.
  2. At the sunroof switch harness connector, using 2 jumper wires, connect one jumper wire to each:
  3. • Sunroof switch open signal circuit
    • Sunroof switch open vent signal circuit
  4. Attempt to slide the sunroof glass towards the closed position, by connecting the other ends of the jumper wires, at the same time, for 3 seconds to the sunroof switch low reference circuit of the sunroof switch harness connector.

Did the sunroof glass slide closed?

--

Go to Step 28

Go to Step 6

6

  1. Remove the jumper wires.
  2. Using a DVM, measure between the reference voltage of the sunroof switch open signal circuit at the sunroof switch harness connector and ground.

Does the voltage measure near the specified value?

B+

Go to Step 7

Go to Step 13

7

With a DVM, measure between the reference voltage of the sunroof switch open vent signal circuit at the sunroof switch harness connector and ground.

Does the voltage measure near the specified value?

B+

Go to Step 8

Go to Step 17

8

With a DVM, measure between the reference voltage between the sunroof switch express signal circuit at the sunroof switch harness connector and ground.

Does the voltage measure near the specified value?

B+

Go to Step 9

Go to Step 33

9

Using a DVM, measure between the reference voltage between the sunroof switch express signal circuit and the sunroof switch low reference circuit at the sunroof switch harness connector.

Does the voltage measure near the specified value?

B+

Go to Step 10

Go to Step 19

10

  1. Disconnect the sunroof module harness connector that contains the sunroof switch signal circuits.
  2. Test for shorts between the sunroof switch signal circuits. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 11

11

  1. Reconnect the sunroof switch to the harness connector.
  2. Reconnect the sunroof module harness connector that contains the sunroof switch signal circuit to the sunroof module.
  3. Disconnect the sunroof motor connector.
  4. Connect a test lamp between the sunroof motor open control and motor close control circuits at the harness connector, module side.

Does the test lamp illuminate?

--

Go to Step 20

Go to Step 12

12

  1. Leave the test lamp between the sunroof motor open control and motor close control circuits at the harness connector, module side.
  2. While observing the test lamp, press the sunroof switch for 3 seconds to the close position then 3 seconds to the open position.

Does test lamp illuminate with each command?

--

Go to Step 30

Go to Step 23

13

Using a DVM, measure between the reference voltage of the sunroof switch open vent signal circuit at the sunroof switch harness connector and ground.

Does the voltage measure near the specified value?

B+

Go to Step 16

Go to Step 14

14

  1. Disconnect the sunroof module harness connector that contains the retained accessory power (RAP) relay switch supply voltage circuit.
  2. Using a DVM, measure between the sunroof RAP relay switch supply voltage circuit at the sunroof module harness connector and ground.

Does the voltage measure near the specified value?

B+

Go to Step 15

Go to Step 31

15

Using a DVM, measure between the sunroof RAP relay switch supply voltage circuit and the ground circuit at the sunroof module harness connector.

Does the voltage measure near the specified value?

B+

Go to Step 29

Go to Step 34

16

Test for the following in the sunroof switch open signal circuit:

    • An open
    • A short to ground
    • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 29

17

Test for the following in the sunroof switch open vent signal circuit:

    • An open
    • A short to ground
    • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 18

18

Inspect for a poor connection in the sunroof switch open vent signal circuit. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 36

19

Test the sunroof switch low reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 29

20

Connect a test lamp between the sunroof motor open control circuit at the harness connector, module side, and ground.

Does the test lamp illuminate?

--

Go to Step 21

Go to Step 22

21

Test the sunroof motor open control circuit for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 37

22

Test the sunroof motor close control circuit for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 36

23

Connect a test lamp between the sunroof motor open control circuit and battery positive voltage at the sunroof motor harness connector.

Does the test lamp illuminate?

--

Go to Step 24

Go to Step 27

24

  1. Connect a test lamp between the sunroof motor open control circuit and ground.
  2. Press the sunroof switch to the open direction for three seconds.

Did the test lamp illuminate?

--

Go to Step 26

Go to Step 25

25

Test the sunroof motor open control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 36

26

Test the sunroof motor close control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 29

27

Test the sunroof motor open control circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 29

28

Inspect for a poor connection at the sunroof switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 35

29

Inspect for a poor connection at the sunroof module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 36

30

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

Did you find and correct the condition?

--

Go to Step 39

Go to Step 38

31

Test for the following in the sunroof RAP relay switch supply voltage circuit:

    • An open
    • A short to ground
    • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 39

Go to Step 32

32

  1. Disconnect the sunroof module harness connector that contains the sunroof motor control circuits.
  2. Test the sunroof motor control circuits for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 39

Go to Retained Accessory Power (RAP) Inoperative in Retained Accessory Power

33

Repair the sunroof switch express signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 39

--

34

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

Did you complete the repair?

--

Go to Step 39

--

35

Replace the sunroof switch. Refer to Sunroof Switch Replacement .

Did you complete the replacement?

--

Go to Step 39

--

36

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

Did you complete the replacement?

--

Go to Step 39

--

37

Replace the sunroof limit switch. Refer to Sunroof Motor/Actuator Replacement .

Did you complete the replacement?

--

Go to Step 39

--

38

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

Did you complete the replacement?

--

Go to Step 39

--

39

  1. Remove any jumper wires.
  2. Reconnect all previously disconnected components.
  3. Replace RAP fuse, if necessary.
  4. Turn ON the ignition, with the engine OFF.
  5. Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3