Pinpoint Test C: One High Beam Headlamp Is Inoperative

Headlamps

Pinpoint Tests

Pinpoint Test C: One High Beam Headlamp Is Inoperative

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

Normal Operation

When the Smart Junction Box (SJB) detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the HIGH BEAM position, the SJB energizes an internal relay. When the relay is energized, the relay routes voltage through circuit CLF08 (YE/VT) to the headlamps. Ground is shared with the low beams.

Vehicles equipped with High Intensity Discharge (HID) headlamps utilize a shutter within each headlamp. When the shutter is activated, the headlamp beam pattern changes to illuminate a greater distance.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Headlamp assembly (HID-equipped only)



PINPOINT TEST C: ONE HIGH BEAM HEADLAMP IS INOPERATIVE

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

NOTE: Make sure the bulb is OK before carrying out diagnostics.

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C1 CHECK THE LOW BEAM OPERATION


- Check the operation of the low beams.
- Do the low beams operate correctly?

Yes
For vehicles with halogen headlamps, REPAIR circuit CLF08 (YE/VT) for an open. TEST the system for normal operation.

For vehicles with HID headlamps, GO to C2.

No
Go To Pinpoint Test B. Pinpoint Test B: One Low Beam Headlamp Is Inoperative

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C2 CHECK THE HIGH BEAM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN


- Place the headlamp switch in the HEADLAMPS ON position.
- Place the multifunction switch in the HIGH BEAM position.
- Measure the voltage between the LH headlamp C1284a-1, circuit CLF08 (YE/VT), harness side and ground; or between the RH headlamp C1285a-1, circuit CLF08 (YE/VT), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
INSTALL a new headlamp assembly. REFER to Headlamp Assembly Service and Repair. TEST the system for normal operation.

No
REPAIR circuit CLF08 (YE/VT) for an open. TEST the system for normal operation.

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