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 Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B3588 00
- Rear Fog Lamp Switch Circuit Malfunction

Diagnostic Fault Information






Circuit/System Description

The rear fog lamp switch signal circuit is grounded momentarily by pressing the rear fog lamp switch. The body control module (BCM) responds to the rear fog lamp request by applying voltage to the rear fog lamp control circuit which illuminates the rear fog lamp.

Conditions for Running the DTC

Battery voltage must be between 9-16 V.

Conditions for Setting the DTC

The BCM detects a short to ground in the turn signal/multifunction switch rear fog lamp signal circuit.

Actions Taken When the DTC Sets

The rear fog lamp indicator on the instrument cluster is always ON.

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

Exterior Lights Schematics Exterior Lights Schematics

Connector End View Reference

Component Connector End Views Fuel Pump and Level Sensor Assembly

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 Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the S78 turn signal/multifunction switch. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 15 ohms between the ground circuit terminal 6 and ground.

• If 15 ohms or greater

1. Ignition OFF.

2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, repair the open/high resistance in the ground connection.

• If less than 15 ohms

3. Ignition ON.

4. Verify the scan tool Rear Fog Lamp Switch parameter is Inactive.

• If not Inactive

1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module.

2. Test for infinite resistance between the signal circuit terminal 12 and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the K9 body control module.

• If Inactive

5. Install a 3 A fused jumper wire between the signal circuit terminal 12 and the ground circuit terminal 6.

6. Verify the scan tool Rear Fog Lamp Switch parameter is Active.

• If not Active

1. Ignition OFF, disconnect the X1 harness connector at the K9 body control module, ignition ON.

2. Test for less than 1 V between the signal circuit terminal 12 and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V

3. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K9 body control module.

• If Active

7. Test or replace the S78 turn signal/multifunction switch.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Turn Signal Switch Replacement Turn Signal Switch Replacement

* Control Module References Control Module References for BCM replacement, programming, and setup