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 CTSY/LAMP fuse supplies battery voltage to the body control module (BCM). The 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, rearview mirror lamps, and rear compartment lamps. The BCM also provides a class 2 serial data message to the driver door module (DDM) and passenger door module (PDM) to apply battery voltage to the exterior courtesy lamps.
Reference Information
Schematic Reference
Interior Lights Schematics (Interior Lights Schematics)
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)
Circuit/System Verification
1. Ignition ON, observe the scan tool dome lamp switch parameter while pressing and releasing the dome lamp switch. The reading should toggle between OFF and ON.
• If the reading does not change between the commanded states, refer to Dome Lamp Switch Malfunction.
2. Observe the scan tool LF door open switch parameter located in Keyless/Remote Start Data while opening and closing the driver door. The reading should toggle between OPEN and CLOSED.
• If the reading does not change between the commanded states, refer to Door Open Switch Malfunction.
3. Observe the scan tool RF door open switch parameter located in Keyless/Remote Start Data while opening and closing the passenger door. The reading should toggle between OPEN and CLOSED.
• If the reading does not change between the commanded states, refer to Door Open Switch Malfunction.
Circuit/System Testing
Dome Lamp Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the I/P dimmer switch.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal 1.
• If the test lamp does not illuminate, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the IPC.
3. Ignition ON, verify the scan tool dome lamp switch parameter is OFF.
• If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the IPC.
4. Install a 3A fused jumper wire between the signal circuit terminal 3 and ground. Verify the scan tool dome lamp 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 IPC.
5. If all circuits test normal, test or replace the I/P dimmer switch.
Door Open Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative door latch assembly.
2. Ignition OFF, interior lamps OFF, doors CLOSED, test for less than 5.0 ohms of resistance between the ground circuit and ground.
• 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 CLOSED.
• If the scan tool displays OPEN, test the 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 and ground. Verify the scan tool door open switch parameter is OPEN.
• 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 inoperative door latch assembly.
Instrument Panel (I/P) Compartment Lamp Malfunction
1. Ignition OFF, disconnect the harness connector at the I/P compartment lamp.
2. Ignition OFF, test for less than 1.0 ohm of resistance 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 courtesy lamp supply voltage circuit terminal A and ground.
• If the test lamp does not illuminate, test the courtesy lamp supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, replace the I/P compartment lamp switch.
Instrument Panel Courtesy Lamps Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative courtesy lamp.
2. Ignition OFF, test for less than 1.0 ohm of resistance between the low control circuit terminal B and ground.
• If greater than the specified range, test the low control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.
3. Ignition ON, verify that a test lamp illuminates between the courtesy lamp supply voltage circuit terminal A and ground.
• If the test lamp does not illuminate, test the courtesy lamp supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
4. Ignition OFF, connect a test lamp between the supply voltage circuit terminal A and the low control circuit terminal B.
5. Command the interior lamps ON with a scan tool. The test lamp should turn ON for 5 seconds and then turn OFF.
• If the test lamp remains ON at all times, test the low control circuit for a short to ground. If the circuits test normal, replace the BCM.
6. If all circuits test normal, replace the inoperative courtesy lamp.
Rear Compartment Courtesy Lamps Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative rear compartment lamp.
2. Open the rear compartment lid.
3. Ignition OFF, exterior lamps OFF, test for less than 5.0 ohms of resistance between the ground circuit terminal B and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance, if the circuits test normal, replace the rear compartment lid latch or pull down actuator.
4. Ignition ON, verify that a test lamp illuminates between the courtesy lamp supply voltage circuit terminal A and ground.
• If the test lamp does not illuminate, test the courtesy lamp supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, replace the inoperative rear compartment lamp.
Underhood Lamp Malfunction
1. Ignition OFF, disconnect the harness connector at the underhood lamp.
2. Ignition OFF, test for less than 5.0 ohms of resistance 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 courtesy lamp supply voltage circuit terminal A and ground.
• If the test lamp does not illuminate, test the courtesy lamp supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, replace the underhood lamp.
Vanity Mirror Lamps Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative vanity mirror.
2. Ignition OFF, scan tool OFF, interior lamps OFF, test for less than 1.0 ohm of resistance 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 courtesy lamp supply voltage circuit terminal A and ground.
• If the test lamp does not illuminate, test the courtesy lamp supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
4. If all circuits test normal, replace the inoperative vanity mirror.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Door Lock Replacement (Door Lock Replacement)
* Sunshade Replacement (Service and Repair)
* Cargo Lamp Replacement (Cargo Lamp Replacement)
* Instrument Panel Courtesy Lamp Bulb Replacement (Instrument Panel Courtesy Lamp Bulb Replacement)
* Instrument Panel Lamp Dimmer Switch Replacement (Service and Repair)
* Underhood Lamp Replacement (Service and Repair)
* Instrument Panel Compartment Lamp Switch Replacement (Service and Repair)
* Rear Compartment Lift Window Latch Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for BCM or IPC replacement, setup, and programming