B2575

DTC B2575

CIRCUIT DESCRIPTION
When the body control module (BCM) senses a request for low beam headlamp illumination, the BCM sends a ground signal to the low beam headlamp relay through the headlamp low beam relay control circuit. The headlamp low beam relay will apply voltage to illuminate the headlamps.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B2575 (Left or generic) Headlamp Control Circuit

CONDITIONS FOR RUNNING THE DTC
The battery voltage must be between 9-16 volts.

CONDITIONS FOR SETTING THE DTC
- When the BCM receives a command to illuminate the low beam headlamps and the headlamp low beam relay control circuit is open or shorted to voltage
- When the BCM does not receive a command to illuminate the low beam headlamps and the headlamp low beam relay control circuit is shorted to ground
- When the low beam relay coil side is open or the battery positive voltage to the low beam relay is open

ACTION TAKEN WHEN THE DTC SETS
The low beam headlamps will not operate or will remain always on.

CONDITIONS FOR CLEARING THE MIL/DTC
- This DTC will clear on current status after the condition for setting the fault is corrected.
- A history DTC will clear after 100 consecutive ignition cycles without a fault present.
- History and current DTCs can be cleared using a scan tool.

TEST DESCRIPTION

Step 1 - Step 13:

The numbers below refer to the step numbers on the diagnostic table.
3. This step tests for voltage at the voltage supply side of the headlamp low beam relay.
4. This step verifies that the BCM is providing ground to the headlamp low beam relay.
5. This step tests if ground is constantly being applied to the headlamp low beam relay.
6. This step tests if there is opposing voltage present or an open headlamp low beam relay control circuit, including the relay coil side.
12. After replacement of the BCM you must calibrate the new module for proper operation.