Courtesy Lamps Malfunction
Courtesy Lamps Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) applies battery voltage to the dome lamp through the dome lamp supply voltage circuit. When any door is opened, the door ajar switch contacts close and the BCM receives a door-ajar input and will supply system voltage to the dome lamp. If the BCM receives a trunk open input, the BCM will activate the rear compartment courtesy lamp supply voltage circuit, providing system voltage to rear compartment courtesy lamp.
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)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, observe the scan tool Door Ajar Switch parameter while opening and closing each vehicle door. The parameter should change between Inactive and Active.
• If the parameter does not change between the selected states, refer to Door Ajar Indicator Malfunction (Door Ajar Indicator Malfunction).
2. Observe the scan tool Rear Closure Ajar Switch parameter while opening and closing the trunk. The parameter should change between Active and Inactive.
• If the parameter does not change between the selected states, refer to Trunk Ajar Indicator Malfunction (Trunk Ajar Indicator Malfunction).
3. Observe the scan tool Interior/Courtesy Lighting Master Switch parameter while turning the courtesy lamp defeat switch ON and OFF. The parameter should change between Active and Inactive.
• If the courtesy lamps do not turn ON and OFF when commanded, refer to Dome Lamp Switch Malfunction.
4. Courtesy lamp defeat switch OFF, observe the scan tool Dome Lamp Switch parameter while turning the dome lamp switch ON and OFF. The parameter should change between Active and Inactive.
• If the courtesy lamps do not turn ON and OFF when commanded, refer to Dome Lamp Switch Malfunction.
5. Command the Courtesy Lamps ON and OFF with a scan tool. The courtesy lamps should turn ON and OFF when changing between the commanded states.
• If the courtesy lamps do not turn ON and OFF when commanded, refer to Dome Lamp Malfunction.
6. Command the Trunk Lamp ON and OFF with a scan tool. Rear compartment courtesy lamp should turn ON and OFF when changing between the commanded states.
• If the rear compartment courtesy lamp does not turn ON and OFF when commanded, refer to Rear Compartment Courtesy Lamp Malfunction.
Circuit/System Testing
Dome Lamp Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the E37A dome/reading lamps.
2. Scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5 ohm between the ground circuit terminal 6 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance
3. Ignition ON, verify the scan tool Interior/Courtesy Lighting Master Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the K9 BCM
4. Verify the scan tool Dome Lamp Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the K9 BCM.
5. Connect 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 Active.
• If not the specified value, test the signal circuit terminal 4 for a short to B+ or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
6. Connect a 3 A fused jumper wire between the signal circuit terminal 5 and ground. Verify the scan tool Dome Lamp Switch parameter is Active.
• If not the specified value, test the signal circuit terminal 5 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
7. If all circuits test normal, replace the E37A dome/reading lamps.
Dome Lamp Malfunction
1. Ignition OFF, disconnect the harness connector at the E37A dome/reading lamps.
2. Test for less than 5 ohm 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. Ignition ON, command the Courtesy Lamps Duty Cycle Command ON and OFF with a scan tool, the test lamp should turn ON and OFF while 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 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 K9 BCM.
5. If all circuits test normal, test or replace the E37A dome/reading lamps.
Rear Compartment Courtesy Lamp Malfunction
1. Ignition OFF, disconnect the harness connector at the E8S rear compartment courtesy lamp.
2. Test for less than 5 ohm between the ground circuit terminal 2 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 1 and ground.
4. Ignition ON, command the Trunk Lamp Command ON and OFF with a scan tool, the test lamp should turn ON and OFF while 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 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 K9 BCM.
5. If all circuits test normal, test or replace the E8S rear compartment courtesy lamp.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Refer to the appropriate replacement procedure for the component causing the condition.
* Control Module References (Programming and Relearning) for BCM replacement, programming and setup