Hazard Lamps Malfunction
Hazard Lamps Malfunction
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.
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 control 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 (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 Verification
1. Ignition ON, individually operate both the left and right turn signals. All appropriate lamps should flash when in each turn signal position.
• If any of the lamps do not flash, refer to Turn Signal Lamps and/or Indicators Malfunction (Turn Signal Lamps and/or Indicators Malfunction).
2. Observe the scan tool Hazard Lamp Switch parameter while cycling the hazard switch. The parameter should change between Active and Inactive.
• If the parameter does not cycle between the specified values, refer to Hazard Switch Circuit Malfunction.
3. Press the hazard switch. All appropriate lamps should flash.
• If one or more lamps do not flash, replace the BCM.
Circuit/System Testing
Hazard Switch Circuit Malfunction
1. Ignition OFF, disconnect the harness connector at the hazard switch.
2. Test for less than 5.0 ohms 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 3A 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 (Acadia) (Service and Repair)Hazard Warning Switch Replacement (Enclave/Traverse) (Service and Repair)Hazard Warning Switch Replacement (OUTLOOK) (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming