• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Hazard Switch Signal | 2 | 1 | -- | -- |
Hazard Switch Ground | -- | 1 | -- | -- |
1. Hazard flashers inoperative 2. Hazard flashers always on |
The hazard switch signal circuit is referenced from battery voltage by the BCM. When the hazard switch is activated, the signal circuit is grounded through the switch and the signal circuit voltage goes low. The BCM then sends an ON-OFF voltage signal through the fuses to the appropriate turn signal and side repeater (export only) lamps or to all of the turn signal fuses for hazard operation.
Interior Lighting Systems Description and Operation
Control Module References for Scan Tool Information
Ignition ON, observe the scan tool hazard lamp switch parameter while operating the hazard switch on and off. The reading should change between active and inactive.
⇒ | 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 G 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 an open/high resistance. If the circuit tests normal, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, programming, and setup |