B2575

DTC B2575 or B2699

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC B2575 02
- Headlamps Control Circuit Short to Ground

DTC B2699 02
- Right Headlamp Control Circuit Short to Ground

Diagnostic Fault Information





Circuit/System Description

When the headlight switch is placed in low beam position, the body control module (BCM) applies a voltage to the head lamps through their respective voltage supply circuits.

Conditions for Running the DTC

The headlamps are turned ON.

Conditions for Setting the DTC

The BCM detects a short to ground on the control circuit.

Action Taken When the DTC Sets

The appropriate headlamp is inoperative.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists.

Reference Information
Schematic Reference

Headlights/Daytime Running Lights (DRL) Schematics (Headlights/Daytime Running Lights (DRL) Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Ignition ON, command the appropriate Headlamp Low Beam ON and OFF with a scan tool. The low beam head lamp should turn ON and OFF when changing between the commanded states.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the appropriate E4 headlamp.
2. Test for less than 5 ohm between the headlamp ground circuit terminal listed below and ground.

* E4G Headlamp - Left low beam terminal B.
* E4H Headlamp - Right low beam terminal B.

• If greater than the specified value, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the headlamp control circuit harness connector listed below and ground.

* E4G Headlamp - Left low beam terminal A.
* E4H Headlamp - Right low beam terminal A.

4. Command the appropriate Headlamp Low Beam test ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
• If the test lamp is always OFF, test the Signal circuit for a short to ground or an open/high resistance. If the circuits test normal, replace the K9 BCM.

5. If all the circuits test normal, replace the E4 headlamp.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Headlamp Replacement (Equinox) (Service and Repair)Headlamp Replacement (Terrain) (Service and Repair)
* Control Module References (Programming and Relearning) for headlamp control module replacement, setup, and programming