Power Sunroof Malfunction
Power Sunroof Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The sunroof electrical system uses a master/slave configuration utilizing a LIN-Bus based system for communication. The body control module (BCM) is designated as the master, while the sunroof control module is configured as the slave.
As the system master, the BCM uses the LIN-Bus communication bus to enable or disable sunroof operation, communicates vehicle information to the controller, and request sunroof movement. The sunroof controller provides system status and diagnostic information to the BCM for diagnostic reporting and operational purposes. The control switch places a different resistor ladder network in the circuit depending on the function selected. The controller analog to digital switch input reads the resulting voltage range and determines the function.
Reference Information
Schematic Reference
Sunroof Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Sunroof Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
Ignition ON, press the sunroof switch to the open and close positions. The sunroof should open and close when changing between the commanded states.
Circuit/System Testing
Note:
Because of the accessibility of the switches, perform the switch component testing before beginning the circuit/system testing.
1. Ignition OFF, disconnect the harness connector at the K61 Sunroof Control Module.
2. Test for less than 30 ohms between the ground circuit terminal 4 and ground.
• If greater than the specified value, test the ground circuit for an open/high resistance.
3. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, determine if the K61 Sunroof Control Module is causing the fuse to open. Replace the K61 Sunroof Control Module.
4. Ignition ON, test for 8-10 V between the signal circuit terminal 11 and ground.
• If less than specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
• If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
5. Ignition OFF, connect the harness connector at the K61 Sunroof Control Module.
6. Ignition OFF, disconnect the harness connector at the S72 Sunroof Switch.
7. Test for less than 30 ohms between the low reference circuit terminal 1 and ground.
• If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K61 Sunroof Control Module.
8. Ignition ON, test for 4.5-5.5 V between the reference voltage circuit terminal 4 and ground.
• If less than specified range, test the reference voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K61 Sunroof Control Module.
• If greater than the specified range, test the reference circuit for a shot to voltage. If the circuit tests normal, replace the K61 Sunroof Control Module.
9. If all circuits test normal, test or replace the S72 Sunroof Switch.
Component Testing
Sunroof Switch
Static Test
1. Ignition OFF, disconnect the harness connector at the S72 Sunroof Switch.
2. Test for 3.5-3.7 kohms between the signal terminal 4 and the low reference circuit terminal 1.
• If not within the specified range, replace the S72 Sunroof Switch.
3. Test for 430-440 ohms between the signal terminal 4 and the low reference circuit terminal 1 while pressing the open switch.
• If not within the specified range, replace the S72 Sunroof Switch.
4. Test for 96-100 ohms between the signal terminal 4 and the low reference circuit terminal 1 while pressing the express open switch.
• If not within the specified range, replace the S72 Sunroof Switch.
5. Test for 1.7-1.8 kohms between the signal terminal 4 and the low reference circuit terminal 1 while pressing the close switch.
• If not within the specified range, replace the S72 Sunroof Switch.
6. Test for 930-940 ohms between the signal terminal 4 and the low reference circuit terminal 1 while pressing the express close switch.
• If not within the specified range, replace the S72 Sunroof Switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Sunroof Opening Position Switch Replacement Service and Repair
* Sunroof Actuator Motor Replacement Service and Repair
* Control Module References Control Module References for sunroof motor/actuator replacement, setup, and programming