Cargo Lamps Malfunction
Cargo 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 cargo lamp on the vehicle exterior is supplied voltage by a dedicated courtesy lamp supply voltage circuit. Cargo lamp operation is controlled by a push-button switch on the instrument panel (I/P) that sends a momentary ground signal to the BCM. The BCM will then illuminate the cargo lamp only while the dome lamp is illuminated.
Diagnostic Aids
Verify proper operation of the courtesy and dome lamps prior to diagnosing a cargo lamp condition.
Reference Information
Schematic Reference
Interior Lights Schematics (Interior Lights Diagrams)
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, verify that the cargo lamp switch parameter displays active and inactive while pressing and releasing the cargo lamp switch.
• If the scan tool parameter does not display the correct state in relation to the actual switch position, refer to Cargo Lamp Switch Circuit Test.
2. If the circuits test normal refer to the Cargo Lamp Control Circuit Test.
Circuit/System Testing
Cargo Lamp Switch Circuit Test
1. Ignition OFF, disconnect the headlamp switch connector.
2. Test for less than 5 ohms between the low reference circuit terminal 3 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance.
3. Ignition ON, verify that the scan tool cargo lamp switch parameter displays inactive.
• If the parameter displays active test the switch 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 terminal 10 and the ground circuit terminal 3. Verify the scan tool cargo lamp switch parameter displays active.
• 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 the circuits test normal test or replace the headlamp switch.
Cargo Lamp Control Circuit Test
1. Ignition OFF, disconnect the harness connector at the affected cargo lamp bulb.
2. Test for less than 5 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 the ground circuit terminal B.
4. Turn the dome lamp switch on and operate the cargo lamp switch ON and OFF. 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 an open/high resistance or short to ground. If the circuit tests normal, replace the BCM.
5. If all circuits test normal, test or replace the affected bulb.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Headlamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming