Pinpoint Test E: The High Beams Are Always On
Headlamps
Pinpoint Test E: The High Beams Are Always On
Normal Operation
The Smart Junction Box (SJB) sends voltage signals to the multifunction switch for the high beam and flash-to-pass requests. When the multifunction switch is placed in the FLASH-TO-PASS or HIGH BEAM position, the voltage signal for that input is routed to ground. When the SJB (Smart Junction Box) detects a request for high beams (when the low beams are on) or flash-to-pass, the SJB (Smart Junction Box) energizes the high beam relay (integrated into the SJB (Smart Junction Box)), which routes voltage to the high beams.
- DTC B1510 (Flash To Pass Switch Circuit Short to Ground)- an on-demand DTC that sets when the SJB (Smart Junction Box) detects a short to ground from the flash-to-pass request input circuit.
- DTC B2A23 (High Beam Input Circuit Short to Ground)- an on-demand DTC that sets when the SJB (Smart Junction Box) detects a short to ground from the high beam request input circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Multifunction switch
- Body builder equipment
- SJB (Smart Junction Box)
PINPOINT TEST E : THE HIGH BEAMS ARE ALWAYS ON
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
E1 CHECK FOR MULTIFUNCTION INPUT DTCs
- Review the DTCs recorded from the SJB (Smart Junction Box) self-test.
Was DTC B1510 or DTC B2A23 retrieved?
Yes
GO to E4.
No
GO to E2.
E2 CHECK THE SJB (Smart Junction Box) HIGH BEAM OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: SJB (Smart Junction Box) C2280E.
- Ignition ON.
Do the high beams continue to illuminate?
Yes
For all except stripped chassis vehicles, REPAIR circuit CLF08 (YE/VT) for a short to voltage. TEST the system for normal operation.
For stripped chassis vehicles, GO to E3.
No
GO to E5.
E3 ISOLATE THE SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: Body Builder C1010.
- Ignition ON.
Do the high beams continue to illuminate?
Yes
The vehicle is operating correctly. REFER to the body builder manual to continue diagnosis.
No
REPAIR circuit CLF08 (YE/VT) for a short to voltage. TEST the system for normal operation.
E4 CHECK THE MULTIFUNCTION SWITCH
- Ignition OFF.
- Disconnect: Multifunction Switch C202B.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB (Smart Junction Box) Self-Test.
- Clear the DTCs and repeat the SJB (Smart Junction Box) self-test.
Is DTC B1510 or DTC B2A23 still present?
Yes
GO to E5.
No
INSTALL a new multifunction switch. TEST the system for normal operation.
E5 CHECK THE HIGH BEAM AND FLASH-TO-PASS REQUEST INPUT CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB (Smart Junction Box) C2280B.
- Measure the resistance between the multifunction switch C202B-9, circuit CLF17 (WH/OG), harness side and ground; and between the multifunction switch C202B-11, circuit CLF27 (GN/BN), harness side and ground.
Are the resistances greater than 10,000 ohms?
Yes
GO to E6.
No
REPAIR the circuit in question for a short to ground. TEST the system for normal operation.
E6 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.