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Makes 🢒 Chevrolet 🢒 2005 🢒 Blazer - 2WD 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Power Sunroof Inoperative

Power Sunroof Inoperative ZRX/XTREME

Diagnostic Aids

If the power sunroof system fuse is open and a short to ground in the accessory voltage circuit is not detected, the fault could be a short to ground in one of the power sunroof control circuits. This would open the power sunroof system fuse when the sunroof switch is pressed.

Test Description

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

  1. This step tests the integrity of the battery positive voltage circuit not the fuse.

Step

Action

Yes

No

Schematic Reference: Sunroof Schematics

Connector End View Reference: Power Roof Systems Connector End Views

1

Did you review the Power Roof Description and Operation?

Go to Step 2

Go to Symptoms - Roof

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
  1. Disconnect the sunroof switch from the harness connector.
  2. Turn ON the ignition, with the engine OFF.
  3. Probe the accessory voltage circuit of the sunroof switch harness connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 5

4

Connect a test lamp between the accessory voltage circuit and the ground circuit of the sunroof switch harness connector.

Does the test lamp illuminate?

Go to Step 7

Go to Step 13

5

Test the accessory voltage circuit of the sunroof switch for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 17

Go to Step 6

6

Probe each of the sunroof motor control circuits of the sunroof switch harness connector with a test lamp that is connected to battery positive voltage.

Did the test lamp illuminate at any of the sunroof motor control circuits?

Go to Step 10

Go to Step 14

7
  1. Connect the sunroof switch to the harness connector.
  2. Connect a test lamp between the sunroof motor open control circuit of the sunroof actuator motor harness connector and a good ground.
  3. Press the sunroof switch to the open position for 3 seconds.

Did the test lamp illuminate?

Go to Step 8

Go to Step 11

8
  1. Connect a test lamp between the sunroof motor close control circuit of the sunroof actuator motor harness connector to a good ground.
  2. Press the sunroof switch to the close position for 3 seconds.

Does the test lamp illuminate?

Go to Step 9

Go to Step 11

9
  1. Connect a test lamp between the sunroof motor open and close control circuits of the sunroof actuator motor harness connector.
  2. Press the sunroof switch to the close position for 3 seconds.

Does the test lamp illuminate?

Go to Step 12

Go to Step 14

10

Repair the short to ground in the sunroof motor/actuator control circuit(s). Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

Go to Step 12

11

Repair the open in the sunroof motor control circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

Go to Step 12

12

Inspect for poor connections at the harness connector of the sunroof actuator 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 17

Go to Step 16

13

Repair the open in the sunroof switch ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 17

Go to Step 14

14

Inspect for poor connections at the harness connector of 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 17

Go to Step 15

15

Replace the sunroof switch. Refer to Sunroof Switch Replacement .

Did you complete the replacement?

Go to Step 17

--

16

Important: Perform the sunroof motor synchronization procedure. Refer to Sunroof Motor/Actuator Synchronization .

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

Did you complete the replacement?

Go to Step 17

--

17
  1. Turn OFF the ignition.
  2. Disconnect any jumper wires.
  3. Connect all previously disconnected components.
  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

Power Sunroof Inoperative Before VIN 209984

Test Description

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

  1. Use a jumper wire to simulate operation of the sunroof to determine if the switch is at fault.

    2.

  2. Disconnecting the sunroof opening position switch harness connector and shorting the sunroof limit switch LS1 circuit, the sunroof module thinks the glass is in the closed position, allowing any request from the sunroof switch to enable an output to the motor for testing.

    3.

  3. When the sunroof module is at rest, the sunroof motor open control and close control circuits are at ground potential. This step is testing for an output to drive the motor, when the sunroof module should be idle.

Step

Action

Values

Yes

No

Schematic Reference: Sunroof Schematics

DEFINITION: Sunroof inoperative, does not open, close, or vent and can be inoperative in any position.

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

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
  1. Turn ON the ignition, with the engine OFF.
  2. Operate the LF window switch.

Does the LF window operate?

--

Go to Step 5

Go to Step 4

4

Operate the radio.

Does the radio operate?

--

Go to Step 30

Go to Retained Accessory Power (RAP) Inoperative in Computer/Integrating System

5

  1. Remove the sunroof switch from the headliner.
  2. Disconnect the sunroof switch from the harness connector.
  3. Observing the position of the sunroof, try to operate the sunroof by connecting a fused jumper between the sunroof switch low reference circuit to either the sunroof switch open signal circuit and/or to the sunroof switch close signal circuit.

Does the sunroof operate normally?

--

Go to Step 33

Go to Step 6

6
  1. Remove the jumper wire.
  2. Measure the reference voltage of the sunroof switch open signal circuit at the sunroof switch harness connector to a good ground.

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 7

Go to Step 17

7

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

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 8

Go to Step 21

8

Measure the reference voltage of the sunroof switch close signal circuit and sunroof switch low reference circuit at the sunroof switch harness connector.

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 9

Go to Step 22

9
  1. Disconnect the sunroof opening position switch harness connector.
  2. Measure the reference voltage of the sunroof limit switch LS1 circuit at the sunroof opening position switch harness connector to a good ground.

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 10

Go to Step 23

10

Measure the reference voltage of the sunroof limit switch LS2 circuit at the sunroof opening position switch harness connector to a good ground.

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 11

Go to Step 24

11

Measure the reference voltage of the sunroof limit switch LS3 circuit at the sunroof opening position switch harness connector to a good ground.

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 12

Go to Step 25

12

Measure the reference voltage between the sunroof limit switch LS3 circuit and the sunroof limit switch low reference circuit at the sunroof opening position switch harness connector.

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 13

Go to Step 26

13

  1. Reconnect the sunroof switch to the harness connector.
  2. Connect a jumper between the sunroof limit switch LS1 circuit and the sunroof limit switch low reference circuit at the sunroof opening position switch harness connector.
  3. Observing the position of the sunroof, operate the system by pressing the sunroof switch to slide the sunroof glass to the available positions, not exceeding the full vent or full open positions.

Does the sunroof glass slide as requested?

--

Go to Step 35

Go to Step 14

14

  1. Wait 15 seconds.
  2. Disconnect the sunroof motor harness connector.
  3. Connect a test lamp between the sunroof motor open control and motor close control circuits at the sunroof motor harness connector, module side.

Does the test lamp illuminate?

--

Go to Step 44

Go to Step 15

15
  1. Leave the test lamp between the sunroof motor control circuits.
  2. Press and hold the sunroof switch to the open position for 3 seconds.

Did the test lamp illuminate?

--

Go to Step 16

Go to Step 27

16
  1. Leave the test lamp between the sunroof motor control circuits.
  2. Press and hold the sunroof switch to the close position for 3 seconds.

Did the test lamp illuminate?

--

Go to Step 34

Go to Step 44

17

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

Does the voltage measure near the specified value?

4.5-5.5 V

Go to Step 18

Go to Step 19

18

Test the sunroof switch open signal circuit for an open, high resistance, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 45

Go to Step 36

19
  1. Disconnect the sunroof module harness connector that contains the retained accessory power (RAP) fuse supply voltage circuit.
  2. Measure the sunroof RAP fuse supply voltage circuit at the sunroof module harness connector to a good ground.

Does the voltage measure near the specified value?

B+

Go to Step 20

Go to Step 37

20

Measure the voltage between the sunroof RAP fuse supply voltage circuit and the sunroof ground circuit at the sunroof module harness connector.

Does the voltage measure near the specified value?

B+

Go to Step 36

Go to Step 38

21

Test the sunroof switch close signal circuit for an open, high resistance, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 45

Go to Step 36

22

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 45

Go to Step 36

23

Test the sunroof limit switch LS1 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 45

Go to Step 36

24

Test the sunroof limit switch LS2 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 45

Go to Step 36

25

Test the sunroof limit switch LS3 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 45

Go to Step 36

26

Test the sunroof limit 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 45

Go to Step 36

27
  1. Connect the test lamp between the sunroof motor open control circuit and a good ground.
  2. Press and hold the sunroof switch to the open position for 3 seconds.

Did the test lamp illuminate?

--

Go to Step  29

Go to Step  28

28

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 45

Go to Step 36

29

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 45

Go to Step 36

30
  1. Remove the POWER WINDOW circuit breaker.
  2. Measure the voltage between the RAP relay switch supply voltage circuit at the circuit breaker and a good ground.

Does the voltage measure near the specified value?

B+

Go to Step 31

Go to Step 39

31

Test the sunroof RAP fuse supply voltage circuit for an open, high resistance, or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 45

Go to Step 32

32

Inspect the power window circuit breaker for poor connections. 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 45

Go to Step 40

33

Inspect for poor connections at the sunroof switch and harness connector. 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 45

Go to Step 41

34

Inspect for poor connections at the sunroof motor and harness connector. 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 45

Go to Step 42

35

Inspect for poor connections at the sunroof opening position switch and harness connector. 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 45

Go to Step 43

36

Inspect for poor connections at the sunroof module and harness connector. 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 45

Go to Step 44

37

Repair an open or high resistance in the sunroof RAP fuse supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 45

--

38

Repair an open in the sunroof ground circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 45

--

39

Repair an open in the RAP relay switch supply voltage circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 45

--

40

Replace the circuit breaker.

Did you complete the repair?

--

Go to Step 45

--

41

Replace the sunroof switch. Refer to Sunroof Switch Replacement .

Did you complete the repair?

--

Go to Step 45

--

42

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

Did you complete the repair?

--

Go to Step 45

--

43

Replace the sunroof opening position switch. Refer to Sunroof Opening Position Switch Replacement .

Did you complete the repair?

--

Go to Step 45

--

44

Replace the sunroof module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the repair?

--

Go to Step 45

--

45
  1. Remove any jumper wires.
  2. Reconnect any connectors.
  3. Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3