Pinpoint Test A: Both Low Beams Are Inoperative

Headlamps

Pinpoint Tests

Pinpoint Test A: Both Low Beams Are Inoperative

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

Normal Operation

The Battery Junction Box (BJB) provides voltage to the Smart Junction Box (SJB) through circuit SBB19 (BU/RD) for the low beam operation.

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- SJB



PINPOINT TEST A: BOTH LOW BEAMS ARE INOPERATIVE

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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A1 CHECK CIRCUIT SBB19 (BU/RD) FOR AN OPEN


- Ignition OFF.
- Disconnect: SJB C2280a.
- Measure the voltage between the SJB C2280a-4, circuit SBB19 (BU/RD), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to A2.

No
VERIFY the BJB fuse 19 (40A) is OK. If OK, REPAIR the circuit. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short.

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A2 CHECK FOR CORRECT SJB OPERATION


- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB 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 SJB. REFER to Body Control Systems. 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. CLEAR the DTCs. REPEAT the self-test.

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