Interior Backlighting Malfunction
Interior Backlighting 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) supplies a voltage reference through the instrument panel (I/P) dimming voltage reference circuit to the interior lamp dimmer switch, which is part of the headlamp switch. When the dimmer switch is placed in a desired brightness position, reference voltage is applied through the dimmer switch rheostat and the I/P lamps dimmer switch signal circuit to the BCM. The BCM interprets this voltage signal, then applies a pulse width modulated (PWM) voltage through the instrument panel lamp supply voltage circuit and the LED dimming supply circuit illuminating the LED and I/P panel lamps.
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 (Programming and Relearning)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 between commanded states.
• If the backlighting does not turn On and OFF or remains ON, replace the driver door switch.
2. Observe the driver heated and cooled seat switch while commanding the Driver Door Switch Non-Integrated Sw. Backlighting Test ON and OFF with a scan tool. The switch backlighting should turn ON and OFF between commanded states.
• If the backlighting does not turn On and OFF or remains ON, refer to Front Door Switch Backlighting Malfunction.
3. 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 between commanded states.
• If the backlighting does not turn On and OFF or remains ON, replace the passenger door switch.
4. Observe the passenger heated and cooled seat switch while commanding the Passenger Door Switch Non-Integrated Sw. Backlighting Test ON and OFF with a scan tool. The switch backlighting should turn ON and OFF between commanded states.
• If the backlighting does not turn On and OFF or remains ON, 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 parameter should change from a high percent to a low percent as the switch is rotated.
• If the parameter does not change, refer to Dimmer Switch Malfunction.
• If the scan tool dimmer control operates normal, refer to Interior Backlighting Malfunction.
Circuit/System Testing
Dimmer Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the headlamp 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. 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. 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 switch.
Interior Backlighting Malfunction
1. Ignition OFF, disconnect the harness connector at the component with the inoperative backlighting.
2. Test for less than 5 ohm between the appropriate ground circuit terminal listed below and ground.
* Headlamp switch terminal 8
* Hazard switch terminal B
* IPC terminal 6
* Ashtray lamp terminal B
* HVAC control module terminal 11 X1
* Radio terminal 8 X1
* Driver information display switch terminal 5
* Traction control switch terminal A
* Reverse lockout solenoid terminal D X2
* Garage door opener transmitter terminal 3
* Sunroof switch terminal 5
* Left rear door window switch terminal F
* Right rear door window switch terminal F
* Right steering wheel control switch terminal 1
* Left steering wheel control switch terminal 8
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Connect a test lamp between the appropriate control circuit terminal listed below and ground.
Incandescent Dimming
* Headlamp switch terminal 7
* Hazard switch terminal A
* IPC terminal B
* Ashtray lamp terminal A
* Traction control switch terminal D
* Reverse lockout solenoid terminal C X2
* Garage door opener transmitter terminal 2
* Sunroof switch terminal 3
* Left rear door window switch terminal B
* Right rear door window switch terminal B
LED Dimming
* HVAC control module terminal 2 - (X2 with C67) or (X3 with CJ2)
* Radio terminal 7 X1
* Driver information display switch terminal 4
* Right steering wheel control switch terminal 2
* Left steering wheel control switch terminal 6
4. Ignition ON, command the appropriate Incandescent Dimming or LED 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, test or replace the component with the inoperative backlighting.
Front Door Switch Backlighting Malfunction
1. Ignition OFF, disconnect the harness connector at the inoperative heated and cooled seat switch.
2. Verify that a test lamp illuminates between the appropriate low reference circuit terminal listed below and B+.
* Driver heated and cool seat switch terminal 3
* Passenger heated and cool seat switch terminal 5
• If the test lamp does not illuminate, test the low reference circuit for an open/high resistance.
3. Connect a test lamp illuminates between the control circuit terminal listed below and ground.
* Driver heated and cool seat switch terminal 5
* Passenger heated and cool seat switch terminal 3
4. Ignition ON, command the appropriate Driver or Passenger Door Switch Non-Integrated Backlighting Test 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 door switch.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the door switch.
5. If all circuits test normal, test or replace the heated and cooled seat switch.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Headlamp Switch Replacement (Service and Repair)
* Hazard Warning Switch Replacement (Service and Repair)
* Ashtray Lamp Bulb Replacement (Service and Repair)
* Electronic Traction Control Switch Replacement (Service and Repair)
* Sunroof Switch Replacement (Service and Repair)
* Rear Side Door Window Switch Replacement (Rear Side Door Window Switch Replacement)
* Driver Information Display Switch Replacement (Service and Repair)
* Steering Wheel Control Switch Assembly Replacement (Service and Repair)
* Transmission Floor Shift Control Indicator Lamp 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)
* Driver Seat Heater Switch Replacement (Driver Seat Heater Switch Replacement)
* Passenger Seat Heater Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for BCM, HVAC, IPC, or Radio replacement, setup, and programming