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 Instructionsprovides an overview of each diagnostic category.

DTC Descriptors
DTC B2580 01
- High Beam Control Circuit Short to Battery

DTC B2580 02
- High Beam Control Circuit Short to Ground

DTC B2580 04
- High Beam Control Circuit Open

Diagnostic Fault Information






Circuit/System Description

The headlamp high beam relay is supplied with battery voltage at all times. The turn signal/multifunction switch signal circuit is grounded by pressing the turn signal/multifunction switch. The body control module (BCM) energizes the headlamp high beam relay by applying ground to the headlamp high beam relay control circuit. When the headlamp high beam relay is energized, the relay switch contacts close and battery voltage is applied through the high beam lamp fuses to the high beam lamp supply voltage circuit which illuminates the high beam lamps.

Conditions for Running the DTC

B2580 01, B2580 02 or B2580 04

High beam lamps ON.

Conditions for Setting the DTC

B2580 01

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

B2580 02

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

B2580 04

The BCM detects an open control circuit.

Action Taken When the DTC Sets

The high beam lamps are inoperative.

Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

Reference Information
Schematic Reference

Exterior Lights Schematics Exterior Lights Schematics

Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1 A4
Description and Operation

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

* 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 Referencesfor scan tool information

Circuit/System Verification

Vehicle in Service Mode, perform the High Beam test. The high beam lamps should be ON/OFF when changing between the commanded states.

Circuit/System Testing

1. Vehicle OFF, disconnect the X1 harness connector at the X50A fuse block - underhood.
2. Verify that a test lamp illuminates between terminal 18 (X1) of the X50A fuse block - underhood and ground

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace X50A fuse block - underhood.

3. Connect a test lamp between B+ and control circuit terminal 18 (X1) of the X50A fuse block - underhood.
4. Command the high beam Lamps 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 control circuit for a short to ground. If the circuit tests normal, replace the K9 BCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

Repair Instructions

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

* Relay Replacement Relay Replacement (Within an Electrical Center)
* Control Module References Control Module References for control module replacement, programming and setup