B2600

DTC B2600

Diagnostic Instructions

* Perform theDiagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC B2600 00
- Daytime Running Lamp Control Circuit




Diagnostic Fault Information






Circuit/System Description

The daytime running lamp (DRL) relay is controlled by the body control module (BCM). The BCM provides ground to the DRL relay control circuit in order to turn ON the DRL relay. When the DRL relay control circuit becomes shorted to voltage, DTC B2600 is set.


Conditions for Running the DTC

The ignition switch is in the ON position.


Conditions for Setting the DTC

The BCM detects a short to voltage in the DRL relay control circuit.


Action Taken When the DTC Sets

* If the high beam relay control circuit is shorted to ground, the high beams are always ON.
* If the high beam relay control circuit is open, the high beam lamps are inoperative.



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 (Headlights/Daytime Running Lights (DRL) Diagrams)
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 (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

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


Circuit/System Verification

Ignition ON, command the DRL ON with a scan tool. The DRL Relay Command parameter should display On and the DRL should illuminate.


Circuit/System Testing

1. Ignition OFF, disconnect the DRL relay.
2. Verify that a test lamp does not illuminate between the relay control circuit terminal 85 and ground.

• If the test lamp illuminates, test the relay control circuit for a short to voltage.

3. If all circuits test normal, replace the BCM.



Repair Instructions

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

* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming