Service Information

Captiva

DTC B2580

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC B2580 00: Headlamp Main beam Control Circuit

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Headlamp Main Beam Relay Control	B2580 00	B2580 00	B2580 00	--

Voltage is applied at all times to the main beam headlamp relay from battery voltage. When the multifunction switch is placed in either the FTP or HIGH position, ground is applied to the body control module (BCM). The BCM then applies a ground to the headlamp main beam relay control circuit. This engages the relay and applies voltage through the HI HEADLAMP fuses to both left and right main beam headlamps.

Conditions for Running the DTC

The ignition is ON. The main beam headlamps must be commanded ON by the multifunction switch.

Conditions for Setting the DTC

The BCM detects a short to ground, open, high resistance, or short to voltage on the headlamp main beam relay control circuit.

Action Taken When the DTC Sets

The main beam headlamps 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.

•	The BCM receives the clear code command from the scan tool.

Reference Information

Schematic Reference

Headlamps/Daytime Running Lamps (DRL) Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

•	Circuit Testing

•	Connector Repairs

•	Testing for Intermittent Conditions and Poor Connections

•	Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, activate the Main beam output control on the scan tool. The Main beam Relay Command parameter in the data list should display On and the main beam headlamps should illuminate.

Circuit/System Testing

Ignition OFF, disconnect the underbonnet fuse block connector C4 and test for a short to voltage, short to ground, an open, or high resistance at the connector terminal H4.
With a scan tool, activate the Main beams output control on the scan tool and test for ground at the underbonnet fuse block connector C4 terminal H4.

⇒	If a ground signal is present, replace the underbonnet fuse block. If a ground signal is not present, replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM replacement, setup, and programming