Pinpoint Test D: The High Beam(s) Are Always On

Headlamps

Pinpoint Tests

Pinpoint Test D: The High Beam(s) Are Always On

Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information. Diagrams By Number

Normal Operation

The Steering Column Control Module (SCCM) monitors input from the multifunction switch. When the multifunction switch is placed in the FLASH-TO-PASS position (first detent when pulled towards the operator) or the headlamp switch is in the HEADLAMPS ON position and the multifunction switch is placed in the HIGH BEAM position (second detent), the SCCM sends a message to the Body Control Module (BCM) over the High Speed Controller Area Network (HS-CAN), indicating a flash-to-pass or high beam request. The BCM then provides voltage to the high beams.

The multifunction switch returns to a rest position when released. The switch positions for the flash-to-pass and high beam features are momentary contact.

- DTC B1007:09 (High-Beam Headlamp Switch: Component Failure) - this DTC sets when the SCCM detects a fault from the multifunction switch input.
- DTC B1D02:15 (Left High Beam Circuit: Circuit Short To Battery or Open) - this DTC sets when the BCM detects a short to voltage from the LH high beam output circuit.
- DTC B1D03:15 (Right High Beam Circuit: Circuit Short To Battery or Open) - this DTC sets when the BCM detects a short to voltage from the RH high beam output circuit.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Multifunction switch
- SCCM
- BCM

PINPOINT TEST D: THE HIGH BEAM(S) ARE ALWAYS ON

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

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D1 CHECK THE MULTIFUNCTION SWITCH INPUT

- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SCCM DataLogger.
- Monitor the SCCM multifunction switch flash-to-pass and high beam PID (HEADLAMP_SW) while placing the multifunction switch in the FLASH-TO-PASS, HIGH BEAM and REST positions.
- Do the PID values agree with the multifunction switch position?

Yes
GO to D2.

No
INSTALL a new multifunction switch. REFER to Steering Column Switches Steering Column Multifunction Switch. TEST the system for normal operation. If the concern still exists, INSTALL a new SCCM. REFER to Steering Column Switches Service and Repair. TEST the system for normal operation.

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D2 CHECK THE BCM HIGH BEAM OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.
- Disconnect: BCM C2280E.
- Ignition ON.
- Do the high beams continue to illuminate?

Yes
REPAIR circuit CLF02 (GY/BN) (LH high beam) or circuit CLF03 (VT/OG) (RH high beam) for a short to voltage. TEST the system for normal operation.

No
GO to D3.

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D3 CHECK FOR CORRECT BCM OPERATION

- Ignition OFF.
- Disconnect all the BCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the BCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new BCM. REFER to Multifunction Electronic Modules Service and Repair. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

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