• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Instrument Panel Lamps Dimmer Select Switch Signal | 2 | 2 | -- | -- |
Instrument Panel Lamps Dimmer Switch Down Signal | 2 | 2 | 2 | -- |
Instrument Panel Lamps Dimmer Switch Up Signal | 2 | 2 | 2 | -- |
Instrument Panel Lamps Control | 1 | 1 | 1 | -- |
Park Lamp Control | 3 | 1 | 3 | -- |
Dimmer/Head Up Display (HUD) Switch Ground | -- | 2 | 2 | -- |
1. Interior Backlighting Malfunction 2. Dimmer Switch Malfunction 3. Park, License, and/or Tail Lamps Malfunction |
The instrument panel cluster (IPC) receives an input from the dimmer/heads up display (HUD) switch. The IPC provides the dimmer/HUD switch with battery positive voltage and ground. The dimmer/HUD switch is a potentiometer that varies the input signal voltage to the IPC. This input determines the intensity level of the backlighting illumination. The driver may change intensity of the backlighting by positioning the dimmer/HUD switch between the minimum and maximum settings. The IPC will default to full intensity if the input from the dimmer/HUD switch is not within the specified values. The backlighting illumination intensity is controlled by the IPC by varying the pulse width modulation (PWM) voltage that feeds the dimming signal circuits of the individual lamps. All interior backlighting lamps are permanently grounded.
Interior Lights Dimming Schematics
Interior Lighting Systems Description and Operation
Control Module References for scan tool information
⇒ | If the reading does not change between the commanded states, refer to Dimmer Switch Malfunction. |
⇒ | If the reading does not change between the commanded states, refer to Dimmer Switch Malfunction. |
⇒ | If the reading does not change between the commanded states, refer to Dimmer Switch Malfunction. |
⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the IPC. |
⇒ | If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the IPC. |
⇒ | 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 IPC. |
⇒ | If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the IPC. |
⇒ | 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 IPC. |
⇒ | If not the specified value, test the signal circuit terminal 7 for a short to ground. If the circuit tests normal, replace the IPC. |
⇒ | 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 IPC. |
⇒ | If the parameter is always ON, test the signal circuit terminal A16 X1 at the IPC for a short to voltage. If the circuit tests normal, replace the IPC. |
⇒ | If the parameter is always OFF, test the signal circuit terminal A16 X1 at the IPC for a short to ground or and open/high resistance. If the circuit tests normal, replace the IPC. |
⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance. |
⇒ | 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 control module associated with the inoperative backlight. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the control module associated with the inoperative backlight. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM, DDM, HVAC, IPC, or PDM replacement, setup, and programming |