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 Circuit | 2 | 1 | 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 headlamps are commanded ON. |
| • | Headlamp dimmer switch must be in the high beam position. |
Conditions for Setting the DTC
The BCM detects a 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
Headlights/Daytime Running Lights (DRL) Schematics
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 BCM connector C4.
- Ignition ON, test for voltage at the BCM harness connector terminal 16.
| ⇒ | If voltage is present, test the control circuit for a short to voltage. If all circuits/connections test normal, replace the underhood fuse block. |
| ⇒ | If voltage 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 |
