Courtesy Lamps Malfunction
Courtesy Lamps Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The interior courtesy lamps consist of the dome lamp and the left and right footwell lamps. Battery voltage is supplied to the courtesy lamps by the body control module (BCM) through an inadvertent power supply circuit. In the event that any of these lamps were to remain illuminated for a period of more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the inadvertent power supply to prevent a total battery discharge condition. Courtesy lamp operation is controlled by the BCM through low side drive control circuits, and any time the inadvertent power supply is active the BCM turns on the courtesy lamps by grounding the control circuits. The BCM will activate the courtesy lamps using inputs from the dome lamp switch on the headlamp switch assembly or any of the door jamb switches. The dome lamp switch signal is monitored from battery voltage by the BCM and when the switch is turned on the signal circuit will be closed to the headlamp switch low reference circuit. The door jamb switch signals are monitored from battery voltage by the BCM and when a door is opened the signal circuit will be grounded through the door jamb switch.
Reference Information
Schematic Reference
Interior Lights Schematics (Interior Lights Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
Interior Lighting Systems Description and Operation (Interior Lighting Systems Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Verify that the courtesy lamp switch parameter displays active and inactive while operating the dimming control/courtesy lamp switch on and off.
• If the scan tool parameter does not display the correct state in relation to the actual switch position, refer to Courtesy Lamp Switch Circuit Test.
2. Verify that the driver door ajar switch parameter displays door open and door closed while opening and closing the driver door.
• If the scan tool parameter does not display the correct state in relation to the actual switch position, refer to Driver Door Jamb Switch Circuit Test.
3. Verify that the passenger door ajar switch parameter displays door open and door closed while opening and closing the front passenger door and rear passenger doors.
• If the scan tool parameter does not display the correct state in relation to the actual switch position, refer to Passenger Door Jamb Switch Circuit Test.
4. If the circuits test normal refer to Courtesy Lamp Control Circuit Test.
Circuit/System Testing
Courtesy Lamp Switch Circuit Test
1. Ignition OFF, disconnect the headlamp switch connector.
2. Test for less than 5 ohms between the low reference circuit terminal 3 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance.
3. Ignition ON, verify that the scan tool courtesy lamp switch parameter displays inactive.
• If the parameter displays active test the switch signal circuit for a short to ground. If the circuit tests normal replace the BCM.
4. Install a 3A fused jumper wire between the signal circuit terminal 11 and the ground circuit terminal 3. Verify the scan tool courtesy lamp switch parameter displays active.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If the circuits test normal test or replace the headlamp switch.
Driver Door Jamb Switch Circuit Test
1. Ignition OFF, disconnect the harness connector at the driver door jamb switch.
2. Test for less than 5 ohms between the ground circuit terminal 2 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool driver door ajar switch parameter is door closed.
• If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 2. Verify the scan tool driver door ajar switch parameter is door ajar.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the driver door ajar switch.
Passenger Door Jamb Switch Circuit Test
1. Ignition OFF, disconnect the harness connector at the affected door jamb switch.
2. Test for less than 5 ohms between the ground circuit terminal 2 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool passenger door ajar switch parameter is door closed.
• If not the specified value, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the ground circuit terminal 2. Verify the scan tool passenger door ajar switch parameter is door ajar.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the affected door jamb switch.
Courtesy Lamp Control Circuit Test
1. Ignition OFF, disconnect the harness connector at the affected courtesy or dome lamp bulb.
2. Ignition ON, verify that a test lamp illuminates between the lamp supply circuit terminal A and ground.
• If the test lamp does not illuminate, test the courtesy lamp supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the BCM.
3. Connect a test lamp between the control circuit terminal B and courtesy lamp supply circuit terminal A.
4. Operate the courtesy lamp switch ON and OFF. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the affected bulb.
Component Testing
Courtesy Lamp Switch Test
1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Test for infinite resistance between the signal terminal 11 and the low reference terminal 3 with the courtesy lamp switch in the off position.
• If not the specified value, replace the headlamp switch.
3. Test for less than 5 ohms between the signal terminal 11 and the low reference terminal 3 with the courtesy lamp switch in the on position.
• If greater than the specified range, replace the headlamp switch.
Door Jamb Switch Test
1. Ignition OFF, disconnect the harness connector at the door jamb switch.
2. Test for infinite resistance between the signal terminal 1 and the ground terminal 2 with the switch in the open position.
• If not the specified value, replace the door jamb switch.
3. Test for less than 5 ohms between the signal terminal 1 and the ground terminal 2 with the switch in the closed position.
• If greater than the specified range, replace the door jamb switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Headlamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming