B3588

DTC B3588

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 Instructionsprovides an overview of each diagnostic category.

DTC Descriptor
DTC B3588 02
- Rear Fog Lamp Switch Circuit Short to Ground

Diagnostic Fault Information






Circuit/System Description

The auxiliary body control module (XBCM) receives a momentary ground signal from the rear fog lamp switch when the switch is activated. The rear fog lamps will remain illuminated until the switch is activated again or when the ignition key is cycled.

Conditions for Running the DTC

System voltage to the XBCM must be 9-16 V.

Conditions for Setting the DTC

The rear fog lamp switch signal circuit is active for longer than 10 minutes.

Action Taken When the DTC Sets

The rear fog lamps will be disabled.

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history status code.
* A history DTC will clear after 50 ignition cycles or with a scan tool using the clear DTCs function.

Reference Information
Schematic Reference

Fog Lights Schematics Fog Lights Schematics
Connector End View Reference

Component Connector End Views Connector End Views By Name
Description and Operation

Exterior Lighting Systems Description and Operation Exterior 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 Relearningfor scan tool information

System Verification

Ignition ON, observe the scan tool Rear Fog Lamp Switch parameter while turning the rear fog lamp switch ON and OFF. The parameter should change between Active and Inactive.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the headlamp and panel dimmer switch.
2. Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 8.

• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

3. Verify the scan tool Rear Fog Lamp Switch parameter displays Inactive.

• If not the specified value, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, replace the XBCM.

4. Install a 3 A fused jumper wire between the signal circuit terminal 6 and the ground circuit terminal 8. Verify the scan tool Rear Fog Lamp Switch parameter is Active.

• 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 XBCM.

5. If all circuits test normal, replace the headlamp and panel dimmer switch.

Repair Instructions

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

* Headlamp Switch Replacement
* Control Module References Programming and Relearningfor XBCM replacement, setup, and programming