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
When the hazard switch is placed in the ON position, ground is momentarily applied through the hazard switch signal circuit to the body control module (BCM). The BCM will detect this voltage drop and will supply battery voltage to all four 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 panel cluster (IPC) 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
1. Ignition ON, observe the scan tool Hazard Lamps Switch parameter while pressing and releasing the hazard switch. The parameter should be Active when the switch is pressed and change to Inactive when the switch is released.
• If the value does not change, refer to the Circuit/System Testing.
2. Observe the function of the right and left turn signal lamps while turning the hazard lamp switch ON and OFF. The right and left turn signal lamps should cycle ON and OFF while the hazard lamp switch is ON and remain OFF when the hazard lamp switch is OFF.
• If a turn signal lamp is always ON or always OFF, refer to Turn Signal Lamps and/or Indicators Malfunction (Turn Signal Lamps and/or Indicators Malfunction)
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the S48C multifunction switch 1 - instrument panel.
2. Test for less than 30 ohm between the ground circuit terminal 7 and ground.
• If greater than the specified value, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that the scan tool Hazard Lamps Switch parameter is Inactive.
• If the value toggles between Inactive and Active, test the signal circuit terminal 10 for a short to ground. If the circuit tests normal, replace the K9 BCM
4. Connect a 3A fused jumper wire between the signal circuit terminal 10 and ground. Observe the scan tool Hazard Lamps Switch parameter. The value should toggle between Inactive and Active.
• If the value is always Inactive, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
5. If all circuits test normal, test or replace the S48C multifunction switch 1 - instrument panel.
Component Testing
1. Ignition OFF, disconnect the harness connector at the S48C Multifunction Switch 1 - Instrument Panel.
2. Test for infinite resistance between the signal terminal 10 and ground terminal 7.
• If less than the specified value, replace the S48C Multifunction Switch 1 - Instrument Panel.
3. Press and hold the hazard switch and test for less than 5 ohm between the signal terminal 10 and ground terminal 7.
• If greater than the specified range, replace the S48C Multifunction Switch 1 - Instrument Panel.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Instrument Panel Multifunction Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup and programming.