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. |
DTC Descriptor
DTC B2575 00: Headlamp Control CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Headlamp Low Beam Relay Control | 2 | 1 | B2575 00 | -- |
1. Headlamps Inoperative - Low Beams 2. Headlamps Always On - Low Beams | ||||
Circuit/System Description
The low beam headlamps are controlled by the body control module (BCM). The BCM grounds the headlamp low beam relay control circuit in order to energize the HID/LO BEAM relay coil. The HID/LO BEAM relay then sends voltage to the low beam headlamps.
Conditions for Running the DTCs
| • | The headlamps are commanded ON. |
| • | The headlamp dimmer switch must be in the low beam position. |
Condition for Setting the DTC
The headlamp low beam relay control circuit is shorted to voltage.
Action Taken When the DTC Sets
The BCM turns off the headlamp low beam relay control for the remainder of the ignition cycle.
Conditions for Clearing the DTC
| • | The conditions for setting the DTC are no longer present. |
| • | A history DTC clears after 100 malfunction-free ignition cycles. |
Reference Information
Schematic Reference
Headlights/Daytime Running Lights (DRL) Schematics
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, command the Low Beam ON with a scan tool. The Low Beam Relay Command parameter should display On and the low beam headlamps should illuminate.
Circuit/System Testing
- Ignition OFF, disconnect the HID/LO BEAM relay.
- Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 86 and ground.
- If all circuits test normal, replace the BCM.
| ⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
