The body control module (BCM) receives battery voltage from the INT LAMPS fuse in order to supply power to the courtesy lamps. The BCM applies this voltage to the courtesy lamps through the courtesy lamp control circuits. When any door or the rear hatch is opened, the door open switch contacts close and the BCM receives a door or rear hatch open signal. The BCM will activate the courtesy lamp control circuit, providing battery voltage to the courtesy lamps. The courtesy lamps can be manually activated by placing the interior lamp switch in the DOME position.

The inadvertent courtesy lamp feature provides a similar function for the interior lamps as the retained accessory power feature. The BCM will energize the inadvertent courtesy lamp control circuit when the BCM is in the active state (awake) and the ignition is OFF. The BCM will continue to supply voltage to the dome, overhead courtesy, and reading lamps after the ignition is turned OFF so that the interior lamps may be operated with there individual on/off switches. In the event that any of these lamps were to remain illuminated for more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the inadvertent courtesy lamp control circuit to prevent a total battery discharge condition.

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. Ignition ON, with a scan tool command the Courtesy Lamp ON and OFF. The cargo, dome, and overhead console/courtesy lamps should turn ON and OFF when commanded.

⇒	If the cargo, dome, and overhead console/courtesy lamps do not illuminate when commanded, refer to Illuminated Entry Lamps Malfunction.

2. Observe the scan tool Driver Door Ajar Sw. parameter while opening and closing the driver door. The parameter should change between Door Closed and Door Ajar.

⇒	If the parameter does not change as the driver door is opened and closed, refer to Door Ajar Indicator Malfunction.

3. Observe the scan tool Passenger Door Ajar Sw. parameter while opening and closing the front passenger and each rear door one at a time. The parameter should change between Door Closed and Door Ajar.

⇒	If the parameter does not change as each door is opened and closed , refer to Door Ajar Indicator Malfunction.

4. Ignition OFF, door OPEN, operate each dome and overhead console courtesy/reading lamps switch ON and OFF. The lamps should turn ON and OFF when activated.

⇒	If the dome and overhead console courtesy/reading lamps do not turn ON and OFF when commanded, refer to Courtesy Lamps Malfunction.

Illuminated Entry Lamps Malfunction - without UUC

1. Ignition OFF, disconnect the X3 and X4 harness connectors at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminals listed below and ground:

•	Terminal 2 X3

•	Terminal 2 X4

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 and X4 harness connectors at the BCM.
4. Disconnect the harness connector at the inoperative courtesy/reading lamp assembly.
5. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5.0 ohms between the appropriate ground circuit terminal listed below and ground.

•	Dome lamp terminal D

•	Overhead console Courtesy/reading lamps terminal B

•	Cargo lamp terminal D

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

6. Connect a test lamp between the appropriate control circuit terminal listed below and ground:

•	Dome lamp terminal A

•	Overhead console Courtesy/reading lamps terminal C

•	Cargo lamp terminal B

7. Command the Courtesy Lamp 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 OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

8. If all circuits test normal, replace the inoperative courtesy/reading lamp assembly.

Illuminated Entry Lamps Malfunction - with UUC

1. Ignition OFF, disconnect the X3 and X4 harness connectors at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminals listed below and ground:

•	Terminal 2 X3

•	Terminal 2 X4

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 and X4 harness connectors at the BCM.
4. Disconnect the harness connector at the dome lamp switch.
5. Connect a test lamp between the control circuit terminal A and ground.
6. Command the Courtesy Lamp 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 OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

7. Ignition OFF, connect the harness connector at the dome lamp switch.
8. Disconnect the harness connector at the inoperative courtesy/reading lamp assembly.
9. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5.0 ohms between the appropriate ground circuit terminal listed below and ground.

•	Dome lamp terminal B

•	Overhead console Courtesy/reading lamps terminal B

•	Cargo lamp terminal D

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

10. Connect a test lamp between the appropriate control circuit terminal listed below and ground:

•	Dome lamp terminal C

•	Cargo lamp terminal B

11. Dome lamp switch in DOOR position, command the Courtesy Lamp 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 OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the dome lamp switch.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the dome lamp switch.

12. If all circuits test normal, replace the inoperative courtesy/reading lamp assembly.

Courtesy Lamps Malfunction - without UUC

1. Ignition OFF, disconnect the X3 and X4 harness connectors at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminals listed below and ground:

•	Terminal 2 X3

•	Terminal 2 X4

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 and X4 harness connectors at the BCM.
4. Disconnect the harness connector at the inoperative courtesy/reading lamp assembly.
5. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5.0 ohms between the appropriate ground circuit terminal listed below and ground.

•	Dome lamp terminal D

•	Overhead console Courtesy/reading lamps terminal B

•	Cargo lamp terminal D

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

6. Ignition ON, verify that a test lamp illuminates between the appropriate control circuit terminal listed below and ground.

•	Dome lamp terminal C

•	Overhead console courtesy/reading lamps terminal A

⇒	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.

7. Remove the INT LAMPS fuse from the I/P fuse block and verify the test lamp turns OFF.

⇒	If the test lamp remains illuminated, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

8. Install the INT LAMPS fuse at the I/P fuse block.
9. Ignition OFF, doors CLOSED, operate the dome lamp switch between the ON and OFF positions. The cargo lamp, dome lamp, and overhead console courtesy/reading lamps should turn ON and OFF.

⇒	If the courtesy lamps do not turn ON and OFF when commanded, replace the dome lamp.

10. If all circuits test normal, replace the inoperative courtesy/reading lamp assembly.

Courtesy Lamps Malfunction - with UUC

1. Ignition OFF, disconnect the X3 and X4 harness connectors at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminals listed below and ground:

•	Terminal 2 X3

•	Terminal 2 X4

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 and X4 harness connectors at the BCM.
4. Disconnect the harness connector at the inoperative courtesy/reading lamp assembly.
5. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5.0 ohms between the appropriate ground circuit terminal listed below and ground.

•	Dome lamp terminal B

•	Overhead console Courtesy/reading lamps terminal B

•	Cargo lamp terminal D

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

6. Ignition ON, verify that a test lamp illuminates between the appropriate control circuit terminal listed below and ground.

•	Dome lamp terminal A

•	Dome lamp switch terminal C

•	Overhead console courtesy/reading lamps terminal A

⇒	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.

7. Remove the INT LAMPS fuse from the I/P fuse block and verify the test lamp turns OFF.

⇒	If the test lamp remains illuminated, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

8. Install the INT LAMPS fuse at the I/P fuse block.
9. Ignition OFF, doors CLOSED, operate the dome lamp switch between the ON and OFF positions. The cargo lamp, dome lamp, and overhead console courtesy/reading lamps should turn ON and OFF.

⇒	If the courtesy lamps do not turn ON and OFF when commanded, test or replace the dome lamp switch.

10. If all circuits test normal, replace the inoperative courtesy/reading lamp assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.