DTC B2580 V6
Circuit Description
When the body control module (BCM) receives a ground signal from the headlamp dimmer switch high beam signal or flash to pass (FTP) switch signal commanding to illuminate the high beam headlamps, the BCM will energize the high beam relay by grounding the high beam relay control circuit.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2580 Headlamp High Beam Control Circuit
Conditions for Running the DTC
The battery voltage must be between 9.0-16.0 volts.
Conditions for Setting the DTC
| • | When the BCM receives a high beam headlamp OFF command and the high beam headlamp relay control circuit is shorted to ground. |
| • | When the BCM receives a high beam headlamp ON command and the high beam headlamp relay control circuit is shorted to voltage or open. |
Action Taken When the DTC Sets
The high beam headlamps will not operate or will remain always on.
Conditions for Clearing the MIL/DTC
| • | This DTC will clear on current status after the condition for setting the fault is corrected. |
| • | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
| • | History and current DTCs can be cleared using a scan tool. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Headlights/Daytime Running Lights (DRL) Schematics Connector End View Reference: Master Electrical Component List | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the high beam relay turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 10 |
4 |
Does the test lamp turn ON and OFF with each command? | Go to Step 8 | Go to Step 5 |
5 | Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 6 |
6 | Test the control circuit of the high beam relay for a short to battery positive voltage or an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 9 |
7 | Test for a short to ground in the high beam headlamp relay control circuit. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 9 |
8 | Inspect for a high resistance or a poor connection at the high beam headlamp relay in the underhood fuse block. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
9 | Inspect for a high resistance or a poor connection at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
10 | Inspect for a high resistance or a poor connection at the harness connectors of the underhood fuse block. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 11 |
11 | Replace the underhood electrical center. Refer to Underhood Electrical Center or Junction Block Replacement . Did you complete the repairs? | Go to Step 14 | -- |
12 | Replace the high beam headlamp relay in the underhood fuse block. Refer to Relay Replacement . Did you complete the repair? | Go to Step 14 | -- |
13 | Replace the BCM . Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 14 | -- |
14 |
Does the DTC reset? | Go to Step 2 | System OK |
DTC B2580 V8
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 2580 00: Headlamp Highbeam Control CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
High Beam Headlamp Relay Control Circuit | 2 | 1 | B2580 | -- |
| ||||
Circuit/System Description
Voltage is applied at all times to the high beam headlamp relay from battery voltage. When the dimmer switch or the flash to pass switch send a ground input to the BCM, the BCM sends a ground output to the high beam relay. The high beam relay is activated then the switch side of the relay closes and turns on the lights.
Conditions for Running the DTC
The ignition is ON. The headlamps must be commanded ON by either the BCM.
Conditions for Setting the DTC
The BCM detects a short to voltage on the high beam headlamps relay control circuit while trying to apply a ground to the circuit.
Action Taken When the DTC Sets
The high beam headlamps are not illuminated.
Conditions for Clearing the DTC
The BCM clears this code from current when the fault is removed from the system.
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, turn the headlamps ON. Turn the high beams ON. The headlamps should illuminate.
Circuit/System Testing
- Ignition OFF, disconnect the C2 high beam harness connector at the BEC.
- Connect a test lamp between the control circuit terminal C6 and B+.
- Command the high beams ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- Ignition OFF, connect the C2 high beams harness connector at the BEC. Disconnect the harness connector at both high beams.
- Test for less than 1.0 ohm of resistance between the appropriate high beam ground circuit terminal B and ground.
- Connect a test lamp between the control circuit terminal A and ground.
- Command the high beams ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, replace the appropriate head lamp bulb assembly.
| ⇒ | 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 an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BEC. |
| ⇒ | If the test lamp is always OFF and the circuit fuse is good, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the BEC. |
| ⇒ | If the test lamp is always OFF and the circuit fuse is open, test the control circuit for a short to ground. If the circuit tests normal, replace the appropriate head lamp bulb assembly. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
