Pinpoint Test A: Both High Beams Are Inoperative
Headlamps
Pinpoint Test A: Both High Beams Are Inoperative
Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information. [1][2]Diagrams By Number
Normal Operation
When the headlamp switch is placed in the HEADLAMPS ON position, the Smart Junction Box (SJB) monitors the high beam request circuit from the multifunction switch. When the multifunction switch is placed in the HIGH BEAM position, the signal is switched to ground, indicating a request for the high beams. The SJB (Smart Junction Box) then energizes the high beam relay (integrated into the SJB (Smart Junction Box)) which supplies voltage to the headlamps.
The SJB (Smart Junction Box) 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 (Smart Junction Box)
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.
A1 CHECK THE HIGH BEAM INDICATOR
- Ignition OFF.
- 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
VERIFY the SJB (Smart Junction Box) fuse 23 (15A) is OK. If OK, GO to A5. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. [1][2]Diagrams By Number
No
GO to A2.
A2 BYPASS THE MULTIFUNCTION SWITCH
- Place the headlamp switch in the OFF position.
- Disconnect: Multifunction Switch C202.
- Place the headlamp switch in the HEADLAMPS ON position.
- 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.
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.
A3 CHECK FOR VOLTAGE TO THE MULTIFUNCTION SWITCH
- Measure the voltage between the multifunction switch C202-6, circuit CLF17 (WH/OG), harness side and ground.
Is the voltage greater than 10 volts?
Yes
REPAIR circuit GD116 (BK/VT) for an open. TEST the system for normal operation.
No
GO to A4.
A4 CHECK THE HIGH BEAM REQUEST INPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB (Smart Junction Box) C2280B.
- Measure the resistance between the multifunction switch C202-6, circuit CLF17 (WH/OG), harness side and the SJB (Smart Junction Box) 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.
A5 CHECK THE SJB (Smart Junction Box) HIGH BEAM OUTPUT CIRCUIT FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Disconnect: SJB (Smart Junction Box) C2280E.
- Connect a fused jumper wire between the SJB (Smart Junction Box) C2280E-1, circuit CDC34 (WH/OG), harness side and the SJB (Smart Junction Box) C2280E-2, circuit CLF08 (YE/VT), harness side.
- Ignition ON.
Do the high beams illuminate?
Yes
REMOVE the jumper wire. GO to A6.
No
REMOVE the jumper wire. REPAIR circuit CLF08 (YE/VT) for an open. TEST the system for normal operation.
A6 CHECK FOR CORRECT SJB (Smart Junction Box) OPERATION
- Disconnect all the SJB (Smart Junction Box) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB (Smart Junction Box) 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 (Smart Junction Box). 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.