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 body control module (BCM) applies battery voltage to the courtesy lamps through 2 separately controlled courtesy lamp supply voltage circuits. When any door is opened, the door ajar switch contacts close and the BCM receives a door-ajar 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 circuits, providing battery voltage to all of the instrument panel (I/P) courtesy lamps, dome lamps, rearview mirror lamps, and rear compartment 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 courtesy lamp control circuits to prevent a total battery discharge condition.
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) for scan tool information
Circuit/System Verification
1. Ignition ON, doors CLOSED, observe the scan tool Ctsy. Lamp Actv. Reason parameter while turning the courtesy lamp defeat switch ON and OFF. The parameter should change between Off and Manual Defeat.
• If the parameter does not change between the commanded states, refer to Courtesy Lamp Defeat Switch Malfunction.
• If the parameter changes between the commanded states, refer to Courtesy Lamps Malfunction.
2. Ignition ON, courtesy lamp defeat switch OFF, observe the scan tool Ctsy. Lamp Actv. Reason parameter while opening and closing each door. The parameter should change between Door Open and Off.
• If the parameter does not change as each door is opened and closed, refer to Door Ajar Indicator Malfunction (Door Ajar Indicator Malfunction).
Circuit/System Testing
Courtesy Lamp Defeat Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the front dome lamp.
2. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5 ohm between the ground circuit terminal 4 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, all doors CLOSED, verify the scan tool Ctsy. Lamp Actv. Reason parameter is Off.
• If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the BCM.
4. Install a 3 A fused jumper wire between the signal circuit terminal 2 and ground. Verify the scan tool Ctsy. Lamp Actv. Reason parameter is Manual Defeat.
• 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, replace the courtesy lamp defeat switch.
Courtesy Lamps Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative courtesy lamp.
2. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5 ohm between the appropriate ground circuit terminal listed below and ground.
* Courtesy lamp - left front door terminal 2
* Courtesy lamp - right front door terminal 2
* Courtesy/reading lamp 2nd row terminal B - with UUC
* Courtesy/reading lamp 2nd row terminal 2 - without UUC
* Front dome lamp terminal 4
* Ignition key lamp terminal F
* I/P compartment lamp terminal 1
* Rear compartment courtesy lamp - left terminal 1
* Rear compartment courtesy lamp - right terminal 1
* Sunshade - left terminal B
* Sunshade - right terminal B
• If greater than the specified range, test the appropriate ground circuit for an open/high resistance.
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground.
* Courtesy lamp - left front door terminal 1
* Courtesy lamp - right front door terminal 1
* Courtesy/reading lamp 2nd row terminal C - with UUC
* Courtesy/reading lamp 2nd row terminal 3 - without UUC
* Front dome lamp terminal 3
* Ignition key lamp terminal E
* I/P compartment lamp terminal 2
* Rear compartment courtesy lamp - left terminal 2
* Rear compartment courtesy lamp - right terminal 2
* Sunshade - left terminal A
* Sunshade - right terminal A
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 ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.
• 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.
5. If all circuits test normal, replace the inoperative courtesy lamp.
Reading Lamps Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative courtesy/reading lamp assembly.
2. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5 ohm between the appropriate ground circuit terminal listed below and ground.
* Courtesy/reading lamp 2nd row terminal B - with UUC
* Courtesy/reading lamp 2nd row terminal 2 - without UUC
* Front dome lamp terminal 4
• 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 control circuit terminal listed below and ground.
* Courtesy/reading lamp 2nd row terminal A - with UUC
* Courtesy/reading lamp 2nd row terminal 4 - without UUC
* Front dome lamp terminal 3
• 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 VB2 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 courtesy/reading lamp assembly.
Underseat lamp Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative underseat lamp.
2. Ignition OFF, test for less than 5 ohm between the ground circuit terminal D and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, park lamps ON, 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 headlamp switch.
4. 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 headlamp.
5. Ignition ON, park lamps OFF, verify that a test lamp does not illuminate between the control circuit terminal B and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the headlamp switch.
6. Verify that a test lamp does not illuminate between the control circuit terminal C and ground.
• If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the headlamp switch.
7. If all circuits test normal, replace the inoperative underseat lamp.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Reading Lamp Bulb Replacement (Service and Repair)
* Door Lamp Replacement (Door Lamp Replacement)
* Ignition Lock Cylinder Bulb Replacement (Ignition Lock Cylinder Bulb Replacement)
* Overhead Console Reading Lamp and Bulb Replacement (Overhead Console Reading Lamp and Bulb Replacement)
* Instrument Panel Compartment Lamp Switch Replacement (Service and Repair)
* Sunshade Illuminated Mirror Lamp Bulb Replacement (Sunshade Illuminated Mirror Lamp Bulb Replacement)
* Dome Lamp Replacement (Dome Lamp Replacement)
* Headlamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming