Hazard Lamps Malfunction

Hazard Lamps Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* 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/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 supply voltage circuits, illuminating the turn signal lamps.

Circuit/System Verification

1. Ignition ON, individually operate both the left and right turn signals. All applicable 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.

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 applicable 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 X1 at the turn signal/multifunction switch.
2. Test for less than 5.0 ohms of resistance between the ground circuit terminal C 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 G 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 G 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 and open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, test or replace the turn signal/multifunction switch.

Component Testing

Turn Signal/Multifunction Switch

1. Ignition OFF, disconnect the harness connector X1 at the turn signal/multifunction switch.
2. Test for infinite resistance between the signal circuit terminal G and the ground circuit terminal C with the switch in the open position.

• If not the specified value, replace the turn signal/multifunction switch.

3. Test for less than 2.0 ohms of resistance between the signal circuit terminal G and the ground circuit terminal C with the switch in the closed position.

• If greater than the specified range, replace the turn signal/multifunction switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Turn Signal Multifunction Switch Replacement