Pinpoint Test A: Both High Beams Are Inoperative
Headlamps
Pinpoint Tests
Pinpoint Test A: Both High Beams Are Inoperative
Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) monitors the high beam request circuit from the multifunction switch through circuit CLF17 (WH/OG). When the multifunction switch is placed in the HIGH BEAM position, the signal is routed to ground through circuit GD116 (BK/VT). If the low beams are on, the SJB energizes the high beam relay (integrated into the SJB) which supplies voltage to the headlamps through circuit CLF08 (YE/VT).
Circuit CLF08 (YE/VT) only supplies voltage to activate the high beam shutters within the headlamp assemblies. If circuit CLF08 (YE/VT) is supplied voltage when the headlamps are not on, the headlamps do not illuminate.
The SJB communicates to the Instrument Panel Cluster (IPC) (over the communication network) to illuminate the high beam indicator.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Multifunction switch
- SJB
PINPOINT TEST A: BOTH HIGH 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.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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A1 CHECK THE HIGH BEAM INDICATOR
- Ignition ON.
- Place the headlamp switch in the HEADLAMPS ON position.
- Place the multifunction switch in the HIGH BEAM position.
- Does the high beam indicator illuminate?
Yes
GO to A5.
No
GO to A2.
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A2 CHECK THE MULTIFUNCTION SWITCH
- Place the headlamp switch in the OFF position.
- Ignition OFF.
- Disconnect: Multifunction Switch C202.
- Connect a fused jumper wire between the multifunction switch C202-6, circuit CLF17 (WH/OG), harness side and the multifunction switch C202-8, circuit GD116 (BK/VT), harness side.
- Place the headlamp switch in the HEADLAMPS ON position.
- Do the high beams illuminate?
Yes
REMOVE the jumper wire. INSTALL a new multifunction switch. TEST the system for normal operation.
No
REMOVE the jumper wire. GO to A3.
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A3 CHECK THE MULTIFUNCTION SWITCH GROUND CIRCUIT FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the multifunction switch C202-8, circuit GD116 (BK/VT), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to A4.
No
REPAIR circuit GD116 (BK/VT) for an open. TEST the system for normal operation.
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A4 CHECK THE HIGH BEAM REQUEST INPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280b.
- Measure the resistance between the multifunction switch C202-6, circuit CLF17 (WH/OG), harness side and the SJB C2280b-27, circuit CLF17 (WH/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to A6.
No
REPAIR circuit CLF17 (WH/OG) for an open. TEST the system for normal operation.
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A5 CHECK THE HIGH BEAM OUTPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280e.
- NOTE: An assistant may be required to listen for the high beam shutters activating for this step.
- Connect a fused jumper wire between the SJB C2280e-1, circuit CDC34 (WH/OG) (without Intelligent Access (IA)) or CBB36 (BU/BN) (with IA), harness side and the SJB C2280e-2, circuit CLF08 (YE/VT), harness side.
- Ignition ON.
- Do the high beam shutters in the headlamps operate?
Yes
VERIFY the SJB fuse 23 (15A) is OK. If OK, GO to A6. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short.
No
REPAIR circuit CLF08 (YE/VT) for an open. TEST the system for normal operation.
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A6 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. 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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