Pinpoint Test B: Both Low Beams Are Inoperative
Headlamps
Pinpoint Test
Pinpoint Test B: Both Low Beams Are Inoperative
Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information. Diagrams By Number
Normal Operation
When the headlamp switch is placed in the HEADLAMPS ON position, the multifunction switch routes voltage to the Smart Junction Box (SJB). The SJB then routes voltage to the LH and RH low beams.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Multifunction switch
- SJB
PINPOINT TEST B: 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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B1 CHECK THE HIGH BEAMS
- Ignition OFF.
- Place the headlamp switch in the HEADLAMPS ON position.
- Place the multifunction switch in the HIGH BEAM position.
- Do the high beams illuminate?
Yes
GO to B2.
No
GO to Pinpoint Test A. Pinpoint Test A: Both Headlamps Are Inoperative (High Beams And Low Beams)
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B2 BYPASS THE MULTIFUNCTION SWITCH
- Disconnect: Multifunction Switch C202b.
- Connect a fused jumper wire between the multifunction switch C202b-6, circuit SBP23 (WH/RD), harness side and the multifunction switch C202b-9, circuit CLF18 (BU/WH), harness side.
- Do the low beams illuminate?
Yes
REMOVE the jumper wire. INSTALL a new multifunction switch. REFER to Steering Column. TEST the system for normal operation.
No
REMOVE the jumper wire. GO to B3.
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B3 CHECK FOR VOLTAGE TO THE SJB
- Connect: Multifunction Switch C202b.
- Disconnect: SJB C2280c.
- Place the headlamp switch in the HEADLAMPS ON position.
- Measure the voltage between the SJB C2280c-30, circuit CLF18 (BU/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to B4.
No
REPAIR circuit CLF18 (BU/WH) for an open. TEST the system for normal operation.
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B4 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.
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