Pinpoint Test E: The High Beams Are Always On
Headlamps
Pinpoint Test E: The High Beams Are Always On
Refer to Wiring Diagrams Set 85, Headlamps/Autolamps for schematic and connector information. Diagrams By Number
Refer to Wiring Diagrams Set 140, Customer Access for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) sends a reference signal to the multifunction switch through circuits CLF17 (WH/OG) (high beam) and CLF27 (GN/BN) (flash-to-pass). When the multifunction switch is placed in the FLASH-TO-PASS or HIGH BEAM position, the voltage signal is routed to ground. When the SJB detects a request for high beams (when the low beams are on) or flash-to-pass, the SJB energizes the high beam relay (integrated into the SJB), which routes voltage through circuit CLF08 (YE/VT) to the headlamps.
- DTC B1510 (Flash To Pass Switch Circuit Short to Ground) - an on-demand DTC that sets when the SJB 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 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
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.
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E1 CHECK FOR MULTIFUNCTION INPUT DTCs
- Review the DTCs recorded from the SJB self-test.
- Was DTC B1510 or B2A23 retrieved?
Yes
GO to E4.
No
GO to E2.
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E2 CHECK THE HIGH BEAM OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: SJB 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. CLEAR the DTCs. REPEAT the self-test.
For stripped chassis vehicles, GO to E3.
No
GO to E5.
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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 information to continue diagnosis.
No
REPAIR circuit CLF08 (YE/VT) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
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E4 CHECK THE MULTIFUNCTION SWITCH
- Disconnect: Multifunction Switch C202b.
- Do the high beams continue to illuminate?
Yes
GO to E5.
No
INSTALL a new multifunction switch. CLEAR the DTCs. REPEAT the self-test.
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E5 CHECK THE HIGH BEAM AND FLASH-TO-PASS REQUEST INPUT CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB 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. CLEAR the DTCs. REPEAT the self-test.
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E6 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. CLEAR the DTCs. REPEAT the self-test.
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