• | 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 the diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Body Control Module (BCM) 1 Fuse B+ | B1395 03 | B1395 03 | -- | -- |
Body Control Module (BCM) 7 Fuse B+ | B2652 00 | B2652 00 | -- | -- |
I/P Dimming Voltage Reference | B1395 03 | B2652 00 | B1395 07 | -- |
I/P Dimmer Switch Signal | B1395 03 | 1 | 1 | -- |
I/P Lamps Dimmer Switch Signal | B2652 00 | 1 | 1 | -- |
Indicator Dimming Control | B2625 00 | 1 | 1 | -- |
LED Backlight Dimming Control | B2610 00 | 1 | 1 | -- |
I/P Dimmer Switch Low Reference | -- | 1 | -- | -- |
I/P Dimmer Switch Ground | -- | 1 | -- | -- |
1. Interior Backlighting Malfunction |
The instrument panel (I/P) dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The I/P dimmer switch provides a voltage signal that will increase as the brightness of the light are increased and decrease as the brightness of the lights are decreased. The body control module (BCM) provides a low reference signal and a B+ voltage reference to the I/P dimmer switch. When the I/P dimmer switch is placed in the desired position, the dimmed voltage setting is applied from the I/P dimmer switch through the I/P dimmer switch signal circuit to the BCM. The BCM interprets the signal and applies the dimmed voltage to the I/P lamps supply voltage circuit and the interior backlighting components dim to the requested level.
Battery voltage must be between 9-16 volts.
The DTC will set for the following conditions:
• | The BCM detects a short to ground in the I/P dimming voltage reference circuit. |
• | The BCM detects a short to ground in the I/P dimmer switch signal circuit. |
• | The BCM detects a short to ground or an open/high resistance in the BCM 1 fuse B+ circuit. |
The DTC will set when the BCM detects a short to voltage in the I/P dimming voltage reference circuit or the vehicles system voltage exceeds the normal operating range of 16 volts.
• | The I/P dimmer switch will not operate. |
• | The I/P dimming lamps will not illuminate. |
• | The condition responsible for setting the DTC no longer exists. |
• | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
Interior Lights Dimming Schematics
Interior Lighting Systems Description and Operation
Control Module References for scan tool information
Ignition ON, observe the scan tool Dimming Control Reference voltage. The reading should display battery voltage.
⇒ | If less than the specified range, refer to Dimming Control Malfunction. |
⇒ | If within the specified range, refer to Dimmer Switch Malfunction. |
⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance. |
⇒ | If less than the specified range, test the voltage reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If greater than the specified range, test the voltage reference circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | 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. |
⇒ | If the test lamp does not illuminate, test the voltage supply circuit for a short to ground or an open/high resistance. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |