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

When the hazard switch is placed in the ON position, ground is momentarily applied through the hazard switch signal circuit to the body control module (BCM). The BCM will detect this voltage drop and will supply 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 panel cluster (IPC) requesting both turn signal indicators to be cycled ON and OFF.

Conditions for Running the DTC

Ignition is ON

Conditions for Setting the DTC

The BCM detects a short to ground on the hazard switch signal circuit for greater than 1 min

Action Taken When the DTC Sets

The hazard lamps will continuously function.

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 DTC.
* A history DTC will clear after 50 ignition cycles.

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 Verification

Ignition ON, observe the scan tool Hazard Lamps Switch parameter while pressing and releasing the hazard switch. The parameter should be Active when the switch is pressed and change to Inactive when the switch is released.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the S48C multifunction switch 1 - instrument panel.
2. Test for less than 30 ohm between the ground circuit terminal 7 and ground.

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

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

• If the parameter toggles between Inactive and Active, test the signal circuit terminal 10 for a short to ground. If the circuit tests normal, replace the K9 BCM

4. Connect a 3A fused jumper wire between the signal circuit terminal 10 and ground. Observe the scan tool Hazard Lamps Switch parameter. The value should toggle between Inactive and Active.

• If the value is always Inactive, 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, test or replace the S48C multifunction switch 1 - instrument panel.

Component Testing

Static Test
1. Ignition OFF, disconnect the harness connector at the S48C Multifunction Switch 1 - Instrument Panel.
2. Test for infinite resistance between the signal terminal 10 and ground terminal 7.

• If less than the specified value, replace the S48C Multifunction Switch 1 - Instrument Panel.

3. Press and hold the hazard switch and test for less than 5 ohm between the signal terminal 10 and ground terminal 7.

• If greater than the specified range, replace the S48C Multifunction Switch 1 - Instrument Panel.

Repair Instructions

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

* Instrument Panel Multifunction Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup and programming.