The body control module (BCM) applies battery voltage to the courtesy lamps through the courtesy lamp supply voltage circuit. When any door is opened, the jam switch contacts close and the BCM receives a door-open input. If the BCM receives a door lock or unlock input or a rear hatch open input, the BCM will activate the courtesy lamp supply voltage circuit, providing battery voltage to all of the instrument panel (I/P) courtesy lamps, dome lamps, rearview mirror lamps, and rear compartment lamps. The BCM also provides a serial data message to the driver door module (DDM) and front passenger door module (PDM) to apply battery voltage to the door courtesy lamps. 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 power courtesy lamp control circuit to prevent a total battery discharge condition.

Schematic Reference

Interior Lights Schematics

Door Lock/Indicator 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 Lamps ON and OFF. The front and rear overhead courtesy lamps should turn ON and OFF when commanded.

⇒	If the overhead courtesy lamps do not illuminate when commanded, refer to Overhead Illuminated Entry Lamps Malfunction.

2. Ignition ON, observe the scan tool Ctsy. Lamp Actv. Reason parameter while turning the dome lamp switch ON and OFF. The reading should toggle between Off and Manual.

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

3. Observe the scan tool Driver Door Open Switch parameter while opening and closing the driver door. The reading should toggle between Active and Inactive.

⇒	If the reading does not change between the commanded states, refer to Door Open Switch Malfunction - Front.

4. Observe the scan tool Passenger Door Open Switch parameter while opening and closing the passenger door. The reading should toggle between Active and Inactive.

⇒	If the reading does not change between the commanded states, refer to Door Open Switch Malfunction - Front.

5. Open each rear door one at a time and observe the courtesy lamps. The courtesy lamps should illuminated when each rear door is opened.

⇒	If the courtesy lamps do not illuminate as each rear door is opened, refer to Door Open Switch Malfunction - Rear.

6. Turn the front and rear reading lamps ON and OFF. The lamps should turn ON and OFF when activated.

⇒	If the reading lamps do not turn ON and OFF, refer to Reading Lamps Malfunction.

Overhead Illuminated Entry Lamps Malfunction

1. Ignition OFF, disconnect the X6 harness connector at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the BCM 3 fuse B+ circuit terminal 1 and ground.

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

3. Ignition OFF, reconnect the X6 harness connector 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 ground circuit terminal B and ground.

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

6. Connect a test lamp between the control circuit terminal A and ground.
7. 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 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.

Door Courtesy Lamp Malfunction - Front

1. Ignition OFF, disconnect the harness connector at the appropriate front door courtesy lamp.
2. Ignition ON, test for less than 20.0 ohms between the low control circuit terminal B and ground.

⇒	If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate door control module.

3. Connect a test lamp between the control circuit terminal A and the control circuit terminal B.
4. Command the Puddle/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 ON, test the control circuit terminal A for a short to voltage. If the circuit tests normal, replace the appropriate door control module.

⇒	If the test lamp is always OFF, test the control circuit terminal A for a short to ground or an open/high resistance. If the circuit tests normal, replace the appropriate door control module.

5. If all circuits test normal, test or replace the appropriate door courtesy lamp.

Door Courtesy Lamp Malfunction - Rear

1. Ignition OFF, disconnect the harness connector at the appropriate rear door courtesy lamp.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal B.

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

3. Connect a test lamp between the control circuit terminal A and the ground circuit terminal B.
4. 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 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.

5. If all circuits test normal, test or replace the appropriate rear door courtesy lamp.

Dome Lamp Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the I/P dimmer switch.
2. Ignition OFF, scan tool OFF, interior lamps OFF, doors CLOSED, test for less than 1.0 ohm between the ground circuit terminal 7 and ground.

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

3. Ignition ON, verify the scan tool Ctsy. Lamp Actv. reason parameter is OFF.

⇒	If not the specified value, test the signal circuit terminal 8 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 8 and ground. Verify the scan tool Ctsy. Lamp Actv. Reason parameter is Manual.

⇒	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 I/P dimmer switch.

Door Open Switch Malfunction - Front

1. Ignition OFF, disconnect the harness connector at the inoperative door latch assembly.
2. Ignition OFF, test for less than 10.0 ohms between the appropriate ground circuit terminal listed below and ground.

•	Driver door latch ground circuit terminal 8

•	Passenger door latch ground circuit terminal 3

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

3. Ignition ON, verify the scan tool Door Open Switch parameter is Inactive.

⇒	If not the specified value, test the appropriate signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the appropriate door control module.

•	Driver door open switch signal circuit terminal 7

•	Passenger door open switch signal circuit terminal 2

4. Install a 3A fused jumper wire between the appropriate signal circuit terminal listed below and ground. Verify the scan tool Door Open Switch parameter is Active.

•	Driver door open switch signal circuit terminal 7

•	Passenger door open switch signal circuit terminal 2

⇒	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 appropriate door control module.

5. If all circuits test normal, replace the inoperative door latch assembly.

Door Open Switch Malfunction - Rear

1. Ignition OFF, disconnect the harness connector at the inoperative rear door latch assembly.
2. Ignition OFF, interior lamps OFF, test for less than 10.0 ohms between the appropriate ground circuit terminal listed below and ground.

•	Left rear door latch assembly ground circuit terminal 6

•	Right rear door latch assembly ground circuit terminal 3

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

3. Ignition ON, verify that a test lamp illuminates between the appropriate door open switch signal circuit terminal listed below and ground.

•	Left rear door open switch signal circuit terminal 5

•	Right rear door open switch signal circuit terminal 2

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

4. Install a 3A fused jumper wire between the appropriate signal circuit terminal listed below and ground. Verify the courtesy lamps illuminate and remain illuminated.

•	Left rear door open switch signal circuit terminal 5

•	Right rear door open switch signal circuit terminal 2

⇒	If the courtesy lamps do not remain illuminated, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, replace the inoperative rear door latch assembly.

Footwell Courtesy Lamp Malfunction

1. Ignition OFF, disconnect the harness connector at the inoperative footwell courtesy lamp.
2. Ignition OFF, scan tool OFF, test for less than 5.0 ohms between the ground circuit terminal B 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 A and ground.
4. 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 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.

5. Remove the BCM 2 fuse 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.

6. If all circuits test normal, replace the inoperative footwell courtesy lamp.

I/P Compartment Lamp Malfunction

1. Ignition OFF, disconnect the harness connector at the I/P compartment lamp.
2. Open the I/P compartment.
3. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal A.

⇒	If the test lamp does not illuminate, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the I/P compartment lamp switch.

4. Ignition OFF, verify that a test lamp illuminates 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.

5. Remove the BCM 2 fuse 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.

6. If all circuits test normal, replace the I/P compartment lamp.

Reading Lamps Malfunction

1. Ignition OFF, disconnect the X2 harness connector at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the BCM 2 fuse B+ circuit terminal 1 and ground.

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

3. Ignition OFF, reconnect the X2 harness connector 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 ground circuit terminal B and ground.

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

6. Ignition OFF, verify that a test lamp illuminates between the control circuit terminal C 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.

7. Remove the BCM 2 fuse 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. If all circuits test normal, replace the inoperative courtesy/reading lamp assembly.

Rear Compartment Courtesy Lamp Malfunction

1. Ignition OFF, disconnect the harness connector at the rear compartment courtesy lamp.
2. Open the trunk.
3. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal B.

⇒	If the test lamp does not illuminate, test the ground circuit for short to voltage or an open/high resistance. If the circuit tests normal, replace the rear compartment release switch.

4. Ignition OFF, verify that a test lamp illuminates between the control circuit terminal C 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.

5. Remove the BCM 2 fuse 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.

6. If all circuits test normal, replace the rear compartment courtesy lamp.

Vanity Mirror Lamps Malfunction

1. Ignition OFF, disconnect the harness connector at the inoperative vanity mirror.
2. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5.0 ohms between the ground circuit terminal B and ground.

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

3. Ignition ON, verify that a test lamp illuminates between the control circuit terminal A 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. Remove the BCM 2 fuse 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.

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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.