GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2007 🢒 G6 🢒 Body Systems 🢒 Lighting 🢒 DTC B2580

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

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the high beam relay ON and OFF.

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

  1. Remove the high beam headlamp relay from the underhood electrical center.
  2. Connect a test lamp between the high beam headlamp relay control circuit and ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 15

5

  1. Disconnect the body control module (BCM) connector C1.
  2. Connect a test lamp between the high beam headlamp relay control circuit and ground.

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
  1. Remove the high beam headlamp relay in the underhood accessory wiring junction block.
  2. Install a fused jumper between the high beam headlamp relay battery positive voltage supply circuit and the switched high beam supply voltage circuit.

Do the high beam headlamps illuminate?

Go to Step 9

Go to Step 17

9
  1. Remove the fused jumper.
  2. Install a test lamp between the high beam headlamp relay switched battery positive voltage supply circuit and the high beam headlamp relay control circuit.
  3. Turn the headlamp switch to the HIGH position.

Does the test lamp illuminate?

Go to Step 15

Go to Step 10

10
  1. Disconnect the electrical center underhood fuse block.
  2. Connect a test lamp between battery positive voltage and the high beam headlamp relay control circuit.
  3. Turn the headlamp switch to the HIGH position.

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
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK