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Hazard Lamps Malfunction

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    • Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Hazard Switch Signal

2

1

1

--

Hazard Switch Indicator Signal

3

3

4

--

Hazard Switch Ground

--

1, 2

--

--

1. Hazard Lamps Inoperative

2. Hazard Lamps Always ON

3. Hazard Switch Indicator Inoperative

4. Hazard Switch Always ON

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 indicator 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 indicator indicators to be cycled ON and OFF.

Reference Information

Schematic Reference

Exterior Lamps Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Exterior Lighting Systems Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References 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 Warning Switch.
  2. Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 3.
    3. ⇒If the test lamp does not illuminate, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify the scan tool Direction Indicator/Hazard Light Command parameter is Inactive.
    4. ⇒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 Direction Indicator/Hazard Light Command parameter is Active.
    5. ⇒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 Warning Switch.

Hazard Switch Indicator Malfunction

  1. Ignition OFF, disconnect the harness connector at the S26 Hazard Warning Switch.
  2. Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 3.
    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 diode test lamp illuminates between the signal circuit terminal 2 and ground in an ON and OFF duty cycle.
    4. ⇒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 Warning Switch.

Hazard Lamp Indicators Malfunction

Ignition ON, command the All Indicators test ON and OFF with the scan tool, verify both indicator indicators changes between turn ON and OFF.

⇒If both indicator indicators change between illuminate and not illuminate during the test, replace the K9 Body Control Module.
⇒If one or both indicator 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 after completing the diagnostic procedure.

    •  Hazard Warning Switch Replacement
    • Control Module References for BCM or instrument cluster replacement, setup, and programming
   


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