Volt

Interior Lights Malfunction

The dome lamp switch has 3 positions: DOOR, OFF, and ON. The ON position provides a ground for continuous operation and the dome lamps will remain illuminated until the switch is placed in either the DOOR or OFF position. When in the DOOR position, the dome lamps operation is controlled by the body control module (BCM). When any door is opened, the door ajar switch contacts close and the BCM receives a door open input. The BCM illuminates the dome lamps when any door is opened or a door lock/unlock request is activated with the key fob. After all doors have been closed, the dome lamps will remain illuminated approximately 3 seconds after the last door closes. When the driver places the dome lamp switch in the OFF position, the dome lamps will be disabled. In the event that the dome lamps were to remain illuminated for more than 10 minutes with the vehicle ON/OFF switch in the OFF position and no doors opened, the BCM will deactivate the dome lamps control circuit to prevent total battery discharge.

Schematic Reference

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. Vehicle in Service Mode, observe the scan tool Door Ajar Switch parameter for each door while opening and closing each vehicle door. The parameter should change between Active and Inactive.

⇒	If the parameter does not change between the selected states, refer to Door Ajar Indicator Malfunction

2. Observe the scan tool Interior/Courtesy Lighting Master Switch parameter while placing the dome lamp switch in the Door, On, and Cancel positions. The parameter should change between Door, On, and Cancel.

⇒	If the parameter does not change between the selected states, refer to Dome Lamp Switch Malfunction.

3. Command the Courtesy Lamps ON and OFF with a scan tool. The front and middle dome lamp should turn ON and OFF when changing between the commanded states.

⇒	If one or both of the dome lamps do not turn ON and OFF when commanded, refer to Dome Lamps Malfunction.

Dome Lamp Switch Malfunction

1. Vehicle OFF, disconnect the harness connector at the E37F Dome/Reading Lamps - Front.
2. Vehicle OFF, scan tool disconnected, all doors closed, all accessories OFF, and wait 2 minutes. Test for less than 10 Ω between the ground circuit terminal 6 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Vehicle in Service Mode, verify the scan tool Interior/Courtesy Lighting Master Switch parameter is Door.

⇒	If the scan tool Interior/Courtesy Lighting Master Switch parameter is Cancel, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the K9 Body Control Module.

⇒	If the scan tool Interior/Courtesy Lighting Master Switch parameter is On, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the K9 Body Control Module.

4. Install a 3 A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool Interior/Courtesy Lighting Master Switch parameter is Cancel.

⇒	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 K9 Body Control Module.

5. Install a 3 A fused jumper wire between the signal circuit terminal 5 and ground. Verify the scan tool Interior/Courtesy Lighting Master Switch parameter is On.

⇒	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 K9 Body Control Module.

6. If all circuits test normal, replace the E37F Dome/Reading Lamps - Front.

Interior Lights Malfunction

1. Vehicle OFF, disconnect the harness connector at the inoperative dome lamp.
2. Vehicle OFF, scan tool disconnected, all doors closed, all accessories OFF, and wait 2 minutes. Test for less than 10 Ω between the ground circuit terminal 6 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the control circuit terminal 2 and ground.
4. Vehicle in Service Mode, command the Courtesy Lamps ON and OFF with a scan tool. 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 voltage. If the circuit tests normal, replace the K9 Body Control Module.

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module.

5. If all circuits test normal, replace the inoperative dome lamp.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.