Hazard Lamps Malfunction

Hazard Lamps Malfunction

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.

Diagnostic Fault Information





Circuit/System Description

The body control module (BCM) controls the hazard lamps based on inputs from the hazard switch. With the hazard switch closed, a ground path is provided on the hazards switch signal circuit, indicating a hazard lamp request. When this request is seen, the BCM will pulse the turn signal lamp supply voltage circuits, illuminating the turn signal lamps.

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 (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 hazard switch.
2. Test for less than 5 ohm between the ground circuit terminal B 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 Lamp Switch parameter is Inactive.

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

4. Install a 3 A fused jumper wire between the signal circuit terminal C and the ground circuit terminal B. Verify the scan tool Hazard Lamp Switch parameter is Active.

• If not the specified value, test the signal circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the BCM.

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

Repair Instructions

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

* Hazard Warning Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming