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 High Beam Control CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Headlamp High Beam Relay Control | B2580 00 | B2580 00 | B2580 00 | -- |
Circuit/System Description
Voltage is applied at all times to the high 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 high beam relay control circuit. This engages the relay and applies voltage through the HI HEADLAMP fuses to both left and right high beam headlamps.
Conditions for Running the DTC
The ignition is ON. The high 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 high beam relay control circuit.
Action Taken When the DTC Sets
The high 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
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Ignition ON, activate the High Beam output control on the scan tool. The High Beam Relay Command parameter in the data list should display On and the high beam headlamps should illuminate.
Circuit/System Testing
- Ignition OFF, disconnect the underhood 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 High Beams output control on the scan tool and test for ground at the underhood fuse block connector C4 terminal H4.
| ⇒ | If a ground signal is present, replace the underhood fuse block. If a ground signal is not present, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
For BCM replacement, setup, and programming refer to Control Module References .
