Interior Backlighting Malfunction (w/AN3)
Interior Backlighting Malfunction (w/AN3)
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
When the ignition switch is turned to the RUN position, the radio VF display turns ON at maximum brightness. When the park lamps are ON, all incandescent and LED back lighting turn ON at the dimming level indicated by the instrument panel (I/P) dimmer switch. At the same time all VF displays dim to match the indicated dimming level. The panel dimmer switch potentiometer is an input to the body control module (BCM). When the driver selects a dimming setting by moving the I/P dimming switch potentiometer, all incandescent back lighting lamps are provided with a specific voltage. When the I/P dimmer switch is moved from MIN to MAX, all VF displays, as well as all incandescent back lighting respond from minimum intensity to maximum brightness in response to the I/P dimmer switch
Reference Information
Schematic Reference
Interior Lights Dimming Schematics (Interior Lights Dimming Schematics)
Connector End View Reference
Component Connector End Views (Connector End Views By Name)
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 (Control Module References) for scan tool information
Circuit/System Verification
1. Ignition ON, observe the driver door switch while commanding the Driver Door Switch Integrated Sw. Backlighting Test ON and OFF with a scan tool. The switch backlighting should turn ON and OFF when changing between the commanded states.
• If the backlighting does not turn ON and OFF, replace the driver door lock and side window switch.
2. Observe the passenger door switch while commanding the Passenger Door Switch Integrated Sw. Backlighting Test ON and OFF with a scan tool. The switch backlighting should turn ON and OFF when changing between the commanded states.
• If the backlighting does not turn ON and OFF, replace the passenger door lock and side window switch.
3. Observe the driver memory/heated seat switch while commanding the Driver Door Switch Non-Integrated Backlighting Test ON and OFF with a scan tool. The switch backlighting should turn ON and OFF when changing between the commanded states.
• If the backlighting does not turn ON and OFF, refer to Front Door Switch Backlighting Malfunction.
4. Observe the passenger heated seat switch while commanding the Passenger Door Switch Non-Integrated Backlighting Test ON and OFF with a scan tool. The switch backlighting should turn ON and OFF when changing between the commanded states.
• If the backlighting does not turn ON and OFF, refer to Front Door Switch Backlighting Malfunction.
5. Observe the scan tool Dimming Control Signal parameter while operating the dimmer switch from high to low. The reading should change from a high percent to a low percent as the switch is rotated.
• If the reading does not change between the selected states, refer to Dimmer Switch Malfunction.
6. Observe the function of the backlighting components while commanding the LED Dimming or Incandescent Dimming ON and OFF with a scan tool. The backlighting components should turn ON and OFF while changing between the commanded states.
• If the backlighting components do not turn ON and OFF, refer to Interior Backlighting Malfunction.
Circuit/System Testing
Front Door Switch Backlighting Malfunction
1. Ignition OFF, disconnect the harness connector X4 at the door lock and side window switch.
2. Connect a 3 A fused jumper wire between the low reference circuit terminal 4 and ground.
3. Connect a test lamp between the backlight supply voltage circuit terminal 13 and B+. The heated seat switch backlighting should illuminate.
• If the switch backlighting does not illuminate, replace the heated seat switch.
4. If the switch backlighting tests normal, replace the door lock and side window switch.
Dimmer Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the headlamp and panel dimmer switch.
2. Verify that a test lamp illuminates between the ground circuit terminal 8 and B+.
• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Dimming Control Signal parameter is less than 0.1 V.
• If greater than the specified range, test the signal circuit terminal 13 for a short to voltage. If the circuit tests normal, replace the BCM.
4. Ignition ON, test for B+ between the I/P dimming voltage reference circuit terminal 15 and ground.
• If less than the specified value, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
5. Install a 3 A fused jumper wire between the signal circuit terminal 13 and the voltage reference circuit terminal 15. Verify the scan tool BCM Dimming Control Signal parameter is greater than 2.6 V.
• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
6. If all circuits test normal, test or replace the headlamp and panel dimmer switch.
Interior Backlighting Malfunction
Note: Each interior backlighting component may need to be disconnected to isolate a short to voltage or short to ground. Use the schematic to identify the following:
* Backlighting components the vehicle is equipped with.
* Component locations on the backlighting control circuit
* Each component's control and ground circuit terminals
1. Ignition OFF, disconnect the harness connector at any component with inoperative backlighting.
2. Ignition OFF, scan tool disconnected, interior lamps OFF, doors CLOSED, test for less than 5 ohm between the ground circuit and ground.
• If greater than the specified value, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the control circuit and ground.
4. Command the LED Dimming or Incandescent Dimming 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 OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
• If the test lamp is always ON, 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 component with inoperative backlighting.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Front Seat Heater Switch Replacement (Service and Repair)
* Door Lock and Side Window Switch Replacement - Driver Side (Door Lock and Side Window Switch Replacement - Driver Side)
* Door Lock and Side Window Switch Replacement - Passenger Side (Door Lock and Side Window Switch Replacement - Passenger Side)
* Headlamp Switch Replacement (with RPO SLT) (Headlamp Switch Replacement (with RPO SLT))Headlamp Switch Replacement (without RPO SLT) (Headlamp Switch Replacement (without RPO SLT))
* Control Module References (Control Module References) for BCM, door lock and side window switch, IPC, radio, HVAC control module, and rear seat audio controller replacement, programming, and setup.