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 each 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) dimmer switch is used to increase and decrease the brightness of the interior backlighting components. The I/P dimmer switch provides a voltage signal to the body control module (BCM) that will increase as the brightness of the lights are increased and decrease as the brightness of the lights are decreased. The BCM provides a low reference, signal, and B+ voltage reference circuits 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 a pulse width modulated (PWM) voltage through the light emitting diode (LED) dimming control circuits illuminating the interior backlighting to the requested level of brightness.

Conditions for Running the DTC

* Battery voltage must be between 9-16 V.
* Park lamps ON.

Conditions for Setting the DTC

DTC B1395 03
* The BCM detects a short to ground in the I/P dimmer switch B+ reference circuit.
* The BCM detects a short to ground or an open/high resistance in the F10DL fuse B+ circuit.

DTC B1395 07

The BCM detects a short to voltage in the I/P dimmer switch B+ reference circuit.

Actions Taken When the DTC Sets

The interior backlighting defaults to FULL bright.

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 vehicle ON/OFF switch cycles have occurred.

Diagnostic Aids

The I/P dimmer switch B+ reference circuit is a low current circuit that will not illuminate a test lamp.

Reference Information
Schematic Reference

* Interior Lights Dimming Schematics Interior Lights Dimming Schematics
* Body Control System Schematics [1][2]Body Control Systems

Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1
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 Testing

1. Vehicle OFF, disconnect the harness connector at the S16 driver information center switch.
2. Vehicle in Service Mode, verify that a test lamp illuminates between B+ and the low reference circuit terminal 12.

• If the test lamp does not illuminate, test the low reference circuit for a short to voltage or an open/high resistance.

3. Test for B+ between the B+ reference circuit terminal 11 and ground.

• If less than the specified range, test the B+ reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

4. Verify that a test lamp does not illuminate between the B+ reference circuit terminal 11 and ground.

• If the test lamp illuminates, test the B+ reference circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.

5. Verify the scan tool LED Backlight Dimming Command parameter is greater than 40%.

• If less than the specified range, test the signal circuit terminal 10 for a short to voltage. If the circuit tests normal, replace the K9 BCM.

6. Vehicle OFF, install a 3 A fused jumper wire between the B+ reference circuit terminal 11 and the signal circuit terminal 10.
7. Vehicle in Service Mode, verify the scan tool LED Backlight Dimming Command parameter is less than 40%.

• If greater than the specified range, test the signal circuit terminal 10 for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

8. If all circuits test normal, replace the S16 driver information center switch.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Driver Information Display and Multifunction Switch Replacement Driver Information Display and Multifunction Switch Replacement
* Control Module References Programming and Relearning for BCM replacement, setup, and programming