B1840
B1840-SUNROOF OPEN SWITCH INPUT CIRCUIT/PERFORMANCE
For a complete wiring diagram, refer to the Wiring Information. Electrical Diagrams
Theory of Operation
When the ignition is on, the Sunroof Motor/Module supplies 10.5 volts to each of the three switch sense circuits (open, close and vent). When any of the three switches are closed to the switch return circuit, that switch command is sent to the module.
- When Monitored:
Whenever the Sunroof module is awake.
- Set Condition:
Whenever the module has determined that the open switch has been applied for over 15 seconds, there is a short to voltage, a short to ground or an open on the Sunroof Open Switch Sense circuit, this code will set.
1. TEST FOR INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, record and erase the DTCs.
3. Press and release the Sunroof Switch in all positions several times.
4. Wait 30 seconds.
5. With the scan tool, read the DTCs.
Does the scan tool display this DTC as active?
Yes
- Go To 2
No
- The conditions that caused this code to set are not present at this time. Check the switch for any binding conditions, and repair any obvious problems. If no obvious problems were found, use the wiring diagram/schematic as a guide and inspect the wiring and connectors for an intermittent condition.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
2. CHECK THE SUNROOF SWITCH
1. With the scan tool, erase the DTCs.
2. Turn the ignition off.
3. Disconnect the Sunroof Switch harness connector.
4. Turn the ignition on and wait 30 seconds.
5. With the scan tool, read the DTCs.
Does the scan tool display this DTC as active?
Yes
- Go To 3
No
- Replace the Sunroof Switch.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
3. CHECK THE (Q3) SUNROOF OPEN SWITCH SENSE CIRCUIT FOR A SHORT TO VOLTAGE
NOTE: To further diagnose the sunroof, it is necessary to lower or remove the headliner.
1. Turn the ignition off.
2. Lower the headliner to gain access to the Sunroof Motor/Module harness connector.
3. Disconnect the Sunroof Motor/Module harness connector.
NOTE: Make sure the A-Pillar and all sunroof inline connectors are connected before proceeding.
4. Turn the ignition on.
5. Measure the voltage between the (Q3) Sunroof Open Switch Sense circuit and Ground in the Sunroof Motor/Module harness connector.
Is there any voltage present?
Yes
- Repair the (Q3) Sunroof Open Switch Sense circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Go To 6
4. CHECK THE (Q3) SUNROOF OPEN SWITCH SENSE CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Measure the resistance between the (Q3) Sunroof Open Switch Sense circuit in the Sunroof Motor/Module harness connector and Ground.
Is the resistance below 10k Ohms?
Yes
- Repair the (Q3) Sunroof Open Switch Sense circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Go To 5
5. CHECK THE (Q3) SUNROOF OPEN SWITCH SENSE CIRCUIT FOR AN OPEN
1. Measure the resistance of the (Q3) Sunroof Open Switch Sense circuit between the Sunroof Switch harness connector and the Sunroof Motor/Module harness connector.
Is the resistance below 2.0 Ohms?
Yes
- Repair the (Q3) Sunroof Open Switch Sense circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Go To 6
6. CHECK THE (Q3) SUNROOF OPEN SWITCH SENSE CIRCUIT FOR A SHORT TO THE (Q6) SUNROOF SWITCH RETURN CIRCUIT
1. Turn the ignition off.
2. Measure the resistance between the (Q3) Sunroof Open Switch Sense circuit and the (Q6) Sunroof Switch Return circuit in the Sunroof Motor/Module harness connector.
Is the resistance below 10k Ohms?
Yes
- Repair the (Q3) Sunroof Open Switch Sense circuit for a short to the (Q6) Sunroof Switch Return circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Replace the Sunroof Motor/Module.
- Perform the Drive Motor Teach procedure. Programming and Relearning.
- Perform the BODY VERIFICATION TEST. Body Verification Test.