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 switch is permanently grounded. When the hazard switch is placed in the ON position, ground is applied through the hazard switch signal circuit to the body control module (BCM). The BCM supplies battery voltage to all 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 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 (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
Press the hazard switch to activate the hazard lamps. The hazard switch and the turn indicators on the instrument panel cluster should start flashing.
If the hazard switch does not flash and the turning indicators on the instrument panel do not flash, refer to Hazard Lamps Malfunction.
If the hazard switch does not flash, refer to Hazard Switch Indicator Malfunction.
If the indicators on the instrument panel do not flash, refer to Hazard Lamp Indicators Malfunction.
Circuit/System Testing
Hazard Lamps Malfunction
1. Ignition OFF, disconnect the harness connector at the S26 Hazard Lamps Switch.
2. Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 3.
• If the test lamp does not illuminate, 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 1 for a short to ground. If the circuit tests normal, replace the K9 Body Control Module.
4. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground. 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 an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module.
5. If all circuits test normal, replace the S26 Hazard Lamps Switch.
Hazard Switch Indicator Malfunction
1. Ignition OFF, disconnect the harness connector at the S26 Hazard Lamps Switch.
2. Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 3.
• If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
3. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground. Verify a test lamp illuminates between the signal circuit terminal 2 and ground in an ON and OFF duty cycle.
• If the test lamp does not illuminate, test the signal circuit terminal 2 for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 Body Control Module.
• If the test lamp does illuminate permanently, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the K9 Body Control Module.
4. If all circuits test normal, replace the S26 Hazard Lamps Switch.
Hazard Lamp Indicators Malfunction
Ignition ON, command the All Indicators test ON and OFF with the scan tool, verify both turn signal indicators changes between turn ON and OFF.
If both turn signal indicators changes between illuminate and not illuminate during the test, replace the K9 Body Control Module.
If one or both turn signal indicators do not illuminate during the test or remain illuminated at all times, replace the P16 Instrument Cluster.
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 or instrument cluster replacement, setup, and programming