Lighting
DTC B1395
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 the diagnostic category.
DTC Descriptors
DTC B1395 03
- Device Voltage Reference Output 1 Circuit Voltage Below Threshold
DTC B1395 07
- Device Voltage Reference Output 1 Circuit Voltage Above Threshold
Diagnostic Fault Information
Circuit/System Description
The instrument panel (I/P) lamp 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 lights 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.
Conditions for Running the DTC
Battery voltage must be between 9-16 V.
Conditions for Setting the DTC
B1395 03
The DTC will set for the following conditions:
* The BCM detects a short to ground in the I/P dimmer switch 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.
B1395 07
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 V.
Actions Taken When the DTC Sets
* The I/P dimmer switch will not operate.
* The I/P dimming lamps will not illuminate.
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 Interior Lights Dimming Schematics
Connector End View Reference
Component Connector End Views Connector Views
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
Ignition ON, cover the ambient light sensor. Vary the interior lamp dimming switch from dim to full bright. The lamps should dim and then become full bright.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the I/P Dimmer switch.
2. Ignition OFF, verify that a test lamp illuminates between B+ and the ground circuit terminal 10.
• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Ignition ON, test for B+ between the voltage reference circuit terminal 5 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.
4. Install a 3 A fused jumper wire between the signal circuit terminal 9 and the voltage reference circuit terminal 5. Verify the scan tool Dimming Control Signal parameter is greater than 2.5 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.
5. If all circuits test normal, replace the I/P dimmer switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Dimmer Switch Replacement Service and Repair
* Control Module References Control Module References for BCM replacement, setup, and programming