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 hazard flashers may be activated in any power mode. The hazard warning switch signal circuit is momentarily grounded when the hazard warning switch is pressed. The body control module (BCM) responds to the hazard warning switch signal input by supplying battery voltage to all four turn signal lamps in an ON and OFF duty cycle. When the hazard warning 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.
Reference Information
Schematic Reference
Exterior Lights Schematics Exterior Lights Schematics
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
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 Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify the scan tool Hazard Lamps Switch parameter changes between Active and Inactive while commanding the hazard lamps ON and OFF with the hazard warning switch.
• If the parameter does not change
Refer to Circuit/System Testing.
• If the parameter changes
3. Verify all left and right turn signal lamps turn ON and OFF while commanding the hazard lamps ON and OFF with the hazard warning switch.
• If all turn signal lamps do not turn ON and OFF
Refer to Turn Signal Lamps and/or Indicators Malfunction Turn Signal Lamps and/or Indicators Malfunction
• If all turn signal lamps turn ON and OFF
4. All OK.
Circuit/System Testing
1. Ignition OFF, scan tool disconnected, all doors closed, all accessories OFF, disconnect the harness connector at the A20 radio/HVAC controls. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 5 ohms between the ground circuit terminal 17 and ground.
• If 5 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 5 ohms
3. Ignition ON.
4. Verify the scan tool Hazard Lamps Switch parameter is Inactive.
• If not Inactive
1. Ignition OFF, disconnect the X2 harness connector at the K9 body control module.
2. Test for infinite resistance between the signal circuit terminal 16 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K9 body control module.
• If Inactive
5. Install a 3 A fused jumper wire between the signal circuit terminal 16 and ground.
6. Verify the scan tool Hazard Lamps Switch parameter is Active.
• If not Active
1. Ignition OFF, disconnect the X2 harness connector at the K9 body control module, ignition ON.
2. Test for less than 1 V between the signal circuit terminal and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If Active
7. Test or replace the A20 radio/HVAC controls.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Radio Control Assembly Replacement Radio Control Assembly Replacement
* Control Module References Control Module References for BCM replacement, programming, and setup