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 | 1 | 2 | -- | -- |
Instrument Panel Lamp Supply Voltage | B2625 02 | 4 | 3 | -- |
Hazard Switch Ground | -- | 2 | 2 | -- |
1. Hazard Lamps Always On 2. Hazard Lamps Inoperative 3. Interior Backlighting Does Not Dim 4. Interior Backlighting Inoperative | ||||
Circuit/System Description
The hazard flashers may be activated in any power mode. The hazard switch is permanently grounded through G201. 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 four turn signal lamps in an ON and OFF duty cycle. When the hazard switch is placed in the ON position, the instrument panel cluster (IPC) receives a signal from the BCM via GMLAN requesting both turn signal indicators to be cycled ON and OFF.
Reference Information
Schematic Reference
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF, disconnect the hazard switch. The hazard lamps should turn OFF.
- If all circuits test normal, test or replace the hazard switch.
| ⇒ | If the hazard lamps remain illuminated, repair the hazard switch signal circuit for a short to ground. 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 |
