Power Sunroof Inoperative

Power Sunroof Inoperative

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview





Circuit/System Description

The sunroof control module/motor is located between the headliner and the roof structure, while the sunroof switch is located above the rearview mirror. The sunroof control module supplies voltage to the sunroof switch through the sunroof switch open and close signal circuits. The module also supplies ground to the switch through the sunroof switch low reference circuit. When the roof open or closed switch is pressed, ground is applied through the switch contacts and the appropriate signal circuit to the module. The control module then internally applies battery positive voltage and ground to the appropriate circuits of the reversible power sunroof motor in order to move the sunroof glass panel to the open, close, or vent position.

Diagnostic Aids

* Because of the accessibility of the sunroof switch, perform the sunroof switch component test before beginning the circuit/system testing.
* A short to B+ on one of the sunroof switch signal circuits will open the switch. This fault is not covered in the circuit/system testing.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the motor/actuator assembly.
2. Test for less than 1.0 ohm of resistance between the sunroof motor/actuator ground circuit terminal 1 and ground.

• If greater than 1.0 ohm, repair the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the battery positive voltage circuit and ground.

• If the test lamp does not illuminate, repair the battery positive voltage circuit for a short to ground or an open/high resistance.

4. Verify that a test lamp illuminates between the accessory voltage circuit and ground.

• If the test lamp does not illuminate, repair the accessory voltage circuit for a short to ground or an open/high resistance.

5. Ignition OFF, connect the sunroof motor/actuator assembly harness connector.
6. Disconnect the harness connector at the sunroof switch.
7. Test for less than 5.0 ohms of resistance between the sunroof switch ground circuit terminal B and ground.

• If greater than 5.0 ohms, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the sunroof motor/actuator assembly.

8. Ignition ON, test for B+ between the sunroof switch open signal circuit terminal D and ground.

• If less than B+, test the signal circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the motor/actuator assembly.

9. Test for B+ between the sunroof switch close signal circuit and ground.

• If less than B+, test the signal circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the motor/actuator assembly.

10. If all circuit test normal, replace the sunroof motor/actuator assembly.

Component Testing

Sunroof Switch
1. With the ignition OFF, disconnect the sunroof switch harness connector.
2. Test for infinite resistance between the sunroof switch open signal terminal D and the ground circuit terminal B.

• If less than infinite ohms of resistance, replace the sunroof switch.

3. Test for less than 5.0 ohms of resistance between the sunroof switch open signal terminal D and the ground circuit terminal B while pressing the sunroof open switch.

• If greater than 5.0 ohms of resistance, replace the sunroof switch.

4. Test for infinite resistance between the sunroof switch closed signal terminal E and the ground circuit terminal B.

• If less than infinite ohms of resistance, replace the sunroof switch.

5. Test for less than 5.0 ohms of resistance between the sunroof switch closed signal terminal D and the ground circuit terminal B while pressing the sunroof close switch.

• If greater than 5.0 ohms of resistance, replace the sunroof switch.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

* Sunroof Switch Replacement (Impala) Sunroof Switch Replacement (Monte Carlo)
* Control Module References for sunroof motor/actuator assembly replacement, setup, and programming. Programming and Relearning Verification Tests