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 Descriptors
DTC B2580 01: Headlamp High Beam Control Circuit Short to VoltageDTC B2580 06: Headlamp High Beam Control Circuit Open or Short to Ground
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Flash to Pass Switch Signal | 1 | 1 | 1 | -- |
Headlamp High Beam Relay Control | B2580 06 | B2580 06 | B2580 01 | -- |
Headlamp Low Beam Relay Control | 1 | 1 | 1 | -- |
Headlamp Switch High Beam Signal | 1 | 1 | 1 | -- |
Headlamp Switch Headlamps On Signal | 1 | 1 | 1 | -- |
Headlamp Switch Headlamps Off Signal | 1 | 1 | 1 | -- |
LF High Beam Headlamp Voltage Supply | 1 | 1 | 1 | -- |
LF Low Beam Headlamp Voltage Supply | 1 | 1 | 1 | -- |
RF High Beam Headlamp Voltage Supply | 1 | 1 | 1 | -- |
RF Low Beam Headlamp Voltage Supply | 1 | 1 | 1 | -- |
LF Headlamp Ground | -- | 1 | 1 | -- |
RF Headlamp Ground | -- | 1 | 1 | -- |
Turn Signal/Multifunction Switch Ground | -- | 1 | 1 | -- |
1. Headlamps Malfunction | ||||
Circuit/System Description
When the turn signal/multifunction switch is placed in the headlamps high or flash to pass (FTP) position, ground is applied to the body control module (BCM) through the headlamp high beam signal circuit or the flash to pass switch signal circuit. The BCM then applies ground to the headlamp high beam relay control circuit which energizes the high beam relay, applying battery voltage to the high beam headlamps. For more detailed information concerning headlamp operation refer to Exterior Lighting Systems Description and Operation .
Conditions for Running the DTC
Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
B2580 01
This DTC will set when the BCM detects a short to battery voltage in the headlamp high beam relay control circuit.
B2580 06
This DTC will set when the BCM detects an open or short to ground in the headlamp high beam relay control circuit.
Actions Taken When the DTC Sets
| • | When DTC B2580 01 is present, the high beam headlamps will not operate. |
| • | When DTC B2580 06 is present, the high beam headlamps will remain ON. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | You issue a scan tool CLEAR DTCs command. |
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
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 Testing
- Ignition OFF, disconnect the high beam relay.
- Connect a test lamp between the high beam relay control circuit terminal H1 and the voltage supply circuit terminal F2.
- Command the high beam headlamps ON and OFF with the high beam switch. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, test or replace the high beam relay.
| ⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to voltage or open/high resistance. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
