B3596

DTC B3596

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC B3596 5a
- Hazard Warning Switch Stuck




Diagnostic Fault Information






Circuit/System Description

The hazard flashers may be activated in any power mode. The hazard switch is located on the accessory control panel and is permanently grounded through ground G205. When the hazard switch is placed in the ON position, ground is applied through the hazard switch signal circuit to the instrument panel cluster (IPC). The IPC responds by sending a serial data message to the underhood electrical center (UEC) and the rear electrical center (REC) requesting the front and rear turn signal lamps be illuminated in an ON and OFF duty cycle. The UEC and REC respond by applying voltage to there respective turn signal control circuits illuminating the front and rear turn signal lamps ON and OFF. The IPC is also responsible for cycling both turn signal indicators ON and OFF. The IPC illuminates the hazard switch telltale by applying voltage to the hazard switch telltale signal circuit.


Conditions for Running the DTC

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



Conditions for Setting the DTC

The DTC will set when the IPC detects a short to ground or an open/high resistance in the hazard switch signal circuit.


Actions Taken When the DTC Sets

When DTC B3596 05 is present, the hazard switch signal circuit will be disabled.


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 Views)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

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 hazard switch.
2. Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 2.

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

3. Ignition ON, verify the scan tool Hazard Warning Switch parameter is OFF.

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

4. Install a 3A fused jumper wire between the signal circuit terminal 6 and ground. Verify the scan tool Hazard Warning Switch parameter is ON.

• 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 IPC.

5. If all circuits test normal, replace the hazard switch.



Repair Instructions

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

* Front Seat Heater Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for IPC replacement, setup, and programming