Circuit Description
The high beam relay is controlled by the body control module (BCM). The BCM provides ground to the high beam relay control circuit in order to turn ON the high beam relay. When the high beam relay control circuit opens, becomes shorted to voltage, or becomes shorted to ground without being commanded ON by the BCM, DTC B2580 is set.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B2580 Headlamp High Beam Control Circuit
Conditions for Running the DTC
The ignition switch is in the ON position.
Conditions for Setting the DTC
B2580 01
This DTC will set if there is a short to voltage in the high beam relay control circuit.
B2580 06
This DTC will set if there is an open or short to ground in the high beam relay control circuit.
Action Taken When the DTC Sets
| • | DTC B2580 is stored in the BCM memory. |
| • | If the high beam relay control circuit is shorted to ground, the high beams are always ON. |
| • | If the high beam relay control circuit is open, the high beam lamps 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. |
Diagnostic Aids
| • | The high beam lamps will only illuminate under the following conditions: |
| - | The headlamps are ON. |
| - | The headlamp dimmer switch is in the high position. |
| • | If the DTC is a history DTC, the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections . |
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 | Is DTC 2580 01 present? | Go to Step 4 | Go to Step 7 |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 15 |
5 |
Does the test lamp illuminate? | Go to Step 6 | Go to Step 16 |
6 | Test the high beam headlamp relay control circuit for a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 21 | Go to Step 17 |
7 | Are the high beam headlamps ON at all times? | Go to Step 12 | Go to Step 8 |
8 |
Do the high beam headlamps illuminate? | Go to Step 9 | Go to Step 17 |
9 |
Does the test lamp illuminate? | Go to Step 15 | Go to Step 10 |
10 |
Does the test lamp illuminate? | Go to Step 17 | Go to Step 11 |
11 | Test for high resistance or an open 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 21 | Go to Step 16 |
12 | Disconnect the BCM connector C1. Do the high beam headlamps turn OFF? | Go to Step 16 | Go to Step 13 |
13 | 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 21 | Go to Step 14 |
14 | Remove the high beam headlamp relay from the underhood fuse block. Refer to Relay Replacement . Do the high beam headlamps turn OFF? | Go to Step 15 | Go to Step 17 |
15 | 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 21 | Go to Step 18 |
16 | 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 21 | Go to Step 19 |
17 | 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 21 | Go to Step 20 |
18 | Replace the high beam headlamp relay in the underhood fuse block. Refer to Relay Replacement . Did you complete the repair? | Go to Step 21 | -- |
19 | Replace the BCM. Refer to Control Module References for BCM replacement, setup, and programming. Did you complete the replacement? | Go to Step 21 | -- |
20 | Replace the underhood electrical center. Refer to Underhood Electrical Center or Junction Block Replacement . Did you complete the repairs? | Go to Step 21 | -- |
21 |
Does the DTC reset? | Go to Step 2 | System OK |
