The interior courtesy lamps consist of the dome lamp and the left and right footwell lamps. B+ 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 B+ 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 B+ by the BCM and when a door is opened the signal circuit will be grounded through the door jamb switch.

Schematic Reference

Interior Lights Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Interior Lighting Systems Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

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 the Courtesy Lamp Malfunction.

2. Verify that the appropriate door ajar switch parameter displays door open and door closed while opening and closing the door.

⇒	If the scan tool parameter does not display the correct state in relation to the actual switch position, refer to the Door Jamb Switch Malfunction.

3. Ignition On, fold down the sun visors and verify the vanity lamps illuminate.

⇒	If the lamps do not illuminate, refer to Vanity Mirrors Malfunction.

4. If the circuits test normal, refer to the Courtesy Lamp Malfunction.

Courtesy Lamp Switch Malfunction

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.

Door Jamb Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the inoperative door jamb switch.
2. Test for less than 5 ohm 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 or open/high resistance. 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 appropriate door ajar switch.

Courtesy Lamp Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate courtesy lamp.
2. Ignition ON, verify that a test lamp illuminates between the listed courtesy lamp supply circuit terminal and ground.

•	Dome/Reading Lamps terminal B

•	Dome Lamp terminal B

•	I/P Courtesy Lamp terminal A

⇒	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 listed ground circuit terminals and B+.

•	Dome/Reading Lamps terminal A

•	Dome Lamp terminal A

•	I/P Courtesy Lamp terminal B

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 appropriate bulb.

Vanity Mirrors Malfunction

1. Disconnect the harness connector at the appropriate sun visor.
2. Test for less than 5 ohms between the ground circuit terminal A and ground.

⇒	If the test lamp does not illuminate, repair the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates when connected between the control circuit terminal B and ground.

⇒	If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

4. If all the circuits test normal, replace the inoperative vanity mirror lamp.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.