B2580

DTC B2580

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 B2580 01
- Headlamp High Beam Control Circuit Short to Battery

DTC B2580 02
- Headlamp High Beam Control Circuit Short to Ground

DTC B2580 04
- Headlamp High Beam Control Circuit Open

Diagnostic Fault Information






Circuit/System Description

The high beam and flash to pass functions are contained within the turn signal/multifunction switch. The BCM provides the turn signal/multifunction switch with two signal circuits, the high beam signal circuit and the flash to pass signal circuit. When the low beam headlamps are ON and the turn signal/multifunction switch is placed in the high beam position, ground is applied to the BCM through the high beam signal circuit. The BCM responds to the high beam request by applying ground to the high beam relay control circuit which energizes the high beam relay. With the high beam relay energized, the switch contacts close allowing battery voltage to flow through the high beam fuses to the high beam control circuits illuminating the high beam headlamps.

Conditions for Running the DTC

* Battery voltage must be between 9-16 V.

* High beam headlamps ON.

Conditions for Setting the DTC

DTC B2580 01

The BCM detects a short to voltage in the headlamp high beam relay control circuit.

DTC B2580 02

The BCM detects a short to ground in the headlamp high beam relay control circuit.

DTC B2580 04

The BCM detects an open in the headlamp high beam relay control circuit.

Actions Taken When the DTC Sets

The high beam headlamps and flash to pass will not operate.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.

* A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

Headlights/Daytime Running Lights (DRL) Schematics Headlights/Daytime Running Lights (DRL) Schematics

Connector End View Reference

Component Connector End Views Sunshade - Left

Description and Operation

Exterior Lighting Systems Description and Operation Exterior Lighting Systems

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 Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the X5 harness connector at the K9 body control module, ignition ON.

2. Verify a test lamp illuminates between the control circuit terminal 18 and ground.

• If the test lamp does not illuminate

1. Ignition OFF, disconnect the X2 harness connector at the X50A fuse block - underhood.

2. Test for infinite resistance between the control circuit terminal and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance

3. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the X50A fuse block - underhood.

• If the test lamp illuminates

3. Ignition OFF, connect a 3 A fused jumper between the control circuit terminal 18 and ground.

4. Remove the F38UA fuse at the X50A fuse block - underhood, ignition ON.

5. Verify a test lamp illuminates between the F38UA fuse B+ switch control terminal and ground.

• If the test lamp does not illuminate

1. Ignition OFF, disconnect the X2 harness connector at the X50A fuse block - underhood, ignition ON.

2. Test for less than 1 V between the control circuit terminal 18 and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the X50A fuse block - underhood.

• If the test lamp illuminates

6. Test or replace the K9 body control module.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Fuse Block Replacement Fuse Block Replacement

* Control Module References Control Module References for BCM replacement, programming, and setup