Courtesy Lamps Malfunction
Courtesy Lamps MalfunctionDiagnostic Instructions
^ Perform the [Diagnostic System Check - Vehicle Diagnostic Information] prior to using this diagnostic procedure. Diagnostic System Check - Vehicle Diagnostic Information
^ Review [Strategy Based Diagnosis] for an overview of the diagnostic approach. Strategy Based Diagnosis
^ [Diagnostic Procedure Instructions - Vehicle Diagnostic Information] provides an overview of each diagnostic category. Diagnostic Procedure Instructions - Vehicle Diagnostic Information
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) receives battery voltage from the CTSY/RF TRN fuse in order to supply power to the courtesy lamps. The BCM applies this voltage to the courtesy lamps through the courtesy lamp supply voltage circuits. When any door is opened, the door open switch contacts close and the BCM receives a door-open signal. If the BCM receives a door lock or unlock signal, the BCM will activate the courtesy lamp supply voltage circuit, providing battery voltage to the dome lamps and the left and right footwell courtesy lamps. The courtesy lamps can be manually activated by placing the interior lamp switch in the DOME position. For more detailed information concerning courtesy lamp operation refer to [Interior Lighting Systems Description and Operation]. The BCM receives battery voltage from the INT LAMPS fuse in order to supply power to the inadvertent courtesy lamps. Inadvertent power courtesy lamp feature provides a similar function for the interior lamps as a retained accessory power feature. The BCM will energize the courtesy lamps supply voltage circuit when the BCM is in the active state (awake). When the inadvertent power courtesy lamps supply voltage circuit is energized, it supplies voltage to all the interior lights listed below. The BCM will continue to supply voltage to the interior lamps after the ignition is turned OFF so that the interior lamps may be operated. In the event that any of these lamps were to remain illuminated for a period of more than 20 minutes with the ignition switch in the OFF position and no BCM input activity, the BCM will deactivate the inadvertent power supply voltage circuit to prevent a total battery discharge condition.
Circuit/System Verification
1. Ignition ON, observe the scan tool Driver Door Open Sw. parameter while opening and closing the driver door. The reading should change between Open and Closed.
^ If the Driver Door Open Sw. parameter does not change between Open and Closed, refer to [Door Ajar Indicator Malfunction].
2. Observe the scan tool Passenger Door Open Sw. parameter while opening and closing the front passenger door. The reading should change between Open and Closed.
^ If the Passenger Door Open Sw. parameter does not change between Open and Closed, refer to [Door Ajar Indicator Malfunction].
3. If all scan tool parameters test normal, refer to the appropriate diagnostic procedure listed below.
^ Courtesy Lamp Circuit Test
^ Inadvertent Power Courtesy Lamp Circuit Test
Circuit/System Testing
Courtesy Lamp Circuit Test
1. Ignition OFF, disconnect the X3, X4 harness connectors at the BCM.
2. Verify that a test lamp illuminates between B+ circuits listed below and ground.
^ Terminal 2 X3
^ Terminal 2 X4
^ If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the related courtesy lamp supply voltage circuits for a short to ground.
3. Ignition OFF, connect the BCM harness connectors.
4. Disconnect the harness connector at the inoperative courtesy lamp lamp.
5. Test for less than 5.0 ohms of resistance between the appropriate ground circuit terminal listed below and ground.
^ Dome lamp - terminal B
^ Courtesy/map lamp - terminal D
^ If greater than the specified range, test the ground circuit for an open/high resistance.
6. Connect a test lamp between the appropriate supply voltage circuit terminal listed below and ground.
^ Dome lamp - terminal A
^ Courtesy/map lamp - terminal C
7. Command the 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 supply voltage circuit for a short to voltage. If the circuit tests normal, replace the BCM.
^ If the test lamp is always OFF, test the supply voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
8. If all circuits test normal, test or replace the courtesy lamp bulb.
Inadvertent Power Courtesy Lamps Circuit Test
1. Ignition OFF, disconnect the X3 harness connector at the BCM.
2. Verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.
^ If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the inadvertent power courtesy lamp circuit for a short to ground.
3. Ignition OFF, connect the harness connector at the BCM.
4. Disconnect the harness connector at the inoperative lamp.
5. Test for less than 5.0 ohms of resistance between the appropriate ground circuit terminal listed below and ground.
^ Dome lamp - terminal B
^ Courtesy/map lamp - terminal D
^ If greater than the specified range, test the ground circuit for an open/high resistance.
6. Ignition ON, verify that a test lamp illuminates between the inadvertent power courtesy lamp circuit terminal and ground.
^ Dome lamp - terminal C
^ Courtesy/map lamp - terminal A
^ If the test lamp does not illuminate, test the inadvertent power courtesy lamp circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
7. If all circuits test normal, replace the inoperative lamp.
Repair Instructions
Perform the [Diagnostic Repair Verification - Vehicle Diagnostic Information] after completing the diagnostic procedure. Diagnostic Repair Verification - Vehicle Diagnostic Information
^ [Control Module References] for BCM replacement, setup, and programming Programming and Relearning
^ [Dome Lamp Replacement (Without DVD)]
^ [Cargo Lamp Replacement]