B3596

DTC B3596

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 B3596 00
- Hazard Lamps Request Circuit

Diagnostic Fault Information





Circuit/System Description

The hazard flashers may be activated in any power mode. When the hazard switch signal circuit is momentarily grounded when the hazard switch is pressed. The BCM supplies battery voltage to all four turn signal lamps in an ON and OFF duty cycle. When the hazard switch is activated, the BCM sends a serial data message to the instrument cluster requesting both turn signal indicators to be cycled ON and OFF.

Conditions for Running the DTC

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

Conditions for Setting the DTC

The BCM detects a short to voltage in the hazard switch signal circuit.

Actions Taken When the DTC Sets

The hazard lamps will not operate when the hazard switch is active.

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 (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 Relearning) for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the A20 radio/HVAC controls.
2. Ignition OFF, test for less than 5 ohm between the ground circuit terminal 17 and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Hazard Lamps Switch parameter is Inactive.

• If not the specified value, test the signal circuit terminal 16 for a short to ground. If the circuit tests normal, replace the K9 BCM.

4. Install a 3 A fused jumper wire between the signal circuit terminal 16 and the ground circuit terminal 17. Verify the scan tool Hazard Lamps 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 K9 BCM.

5. If all circuits test normal, replace the A20 radio/HVAC controls

Repair Instructions

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

* Radio Control Assembly Replacement (Radio Control Assembly Replacement)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming