Diagnostic Instructions
| • | 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. |
DTC Descriptors
DTC B1395 03: Device Voltage Reference Output 1 Circuit Voltage Below ThresholdDTC B1395 07: Device Voltage Reference Output 1 Circuit Voltage Above Threshold
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
I/P Dimming 12-Volt Reference | B1395 03, B3600 03 | B3600 03 | -- | -- |
Instrument Panel Lamps Dimmer Switch Signal | B3600 03 | B3600 03 | 1 | -- |
1. Interior Backlighting Inoperative | ||||
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 I/P lamps supply voltage circuit and the LED dimming supply circuit to all related interior lamps, illuminating them to the desired level of brightness.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
B1395 03
The BCM detects a voltage that is lower than 11.8 volts on the I/P dimming voltage reference circuit.
B1395 07
The BCM detects a voltage that is greater than 12.2 volts on I/P dimming voltage reference circuit.
Action Taken When the DTC Sets
The I/P lamps are not illuminated.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
Reference Information
Schematic Reference
Interior Lights Dimming Schematics
Connector End View Reference
Description and Operation
Interior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, cover the ambient light sensor, vary the interior lamp dimming switch from dim to full bright. The I/P lamps should dim and then become full bright.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the headlamp switch.
- Ignition ON, test for 11.8-12.2 volts between the 12-volt reference circuit terminal 15 and ground.
- If all circuits test normal, replace the headlamp switch.
| ⇒ | If greater than the specified range, test the 12-volt reference circuit for short to voltage. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified range, test the 12-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
