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 | -- |
Multifunction Turn Signal Lever Ground | -- | 1, 3 | 1, 3 | -- |
1. Hazard Lamps Inoperative 2. Hazard Lamps Always On 3. Turn Signal Malfunction | ||||
Circuit/System Description
The body control module (BCM) controls the hazard lamps based an input from the hazard lamp switch. When the hazard lamp switch is depressed, a ground signal is provided to the BCM on the hazard switch signal circuit. This indicates to the BCM that the hazard lamps are requested. The BCM will then activate the hazards lamps by pulsing the turn signal lamp supply voltage circuits.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for Scan Tool Information
Circuit/System Verification
- Ignition ON, operate the left and right turn signals using the multifunction turn signal lever. Each of the turn signal lamps should pulse when commanded ON by the lever.
- Observe the scan tool Hazard Switch Signal parameter while cycling the hazard lamp switch ON and OFF. The parameter should change between On and Off.
| ⇒ | If the turn signal lamps do not function as specified, refer to Turn Signal Lamps and/or Indicators Malfunction . |
Circuit/System Testing
- Ignition OFF, disconnect the X1 harness connector at the multifunction turn signal lever.
- Test for less than 5 ohms of resistance between the ground circuit terminal A and ground.
- Ignition ON, verify the scan tool Hazard Switch Signal parameter is Off.
- Install a 3A fused jumper wire between the signal circuit terminal H and ground. Verify the scan tool Hazard Switch Signal parameter is On.
- If all circuits test normal, test or replace the multifunction turn signal lever.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If not the specified value, test the signal circuit terminal H for a short to ground. If the circuit tests normal, replace the BCM. |
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
