Pinpoint Test C: One High Beam Headlamp Is Inoperative
Headlamps
Pinpoint Tests
Pinpoint Test C: One High Beam Headlamp Is Inoperative
Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information. Diagrams By Number
Normal Operation
When the Smart Junction Box (SJB) detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the HIGH BEAM position, the SJB sends voltage through circuits CLF02 (GY/BN) (LH headlamp) and CLF03 (VT/OG) (RH headlamp) to the high beam headlamps.
- DTC B1570 (Lamp Headlamp High-Beam Circuit Short to Ground) - a continuous and on-demand DTC that sets when the SJB detects a short to ground (high amperage draw) from the LH or RH high beam voltage supply circuit. The self-test must be run after the repair in order for the SJB to enable the output for the high beam voltage supply.
- DTC B2505 (LF Lamp High Beam Circuit Failure) - a continuous and on-demand DTC that sets when the SJB detects an open from the LH high beam voltage supply circuit.
- DTC B2507 (RF Lamp High Beam Circuit Failure) - a continuous and on-demand DTC that sets when the SJB detects an open from the RH high beam voltage supply circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- SJB
PINPOINT TEST C: ONE HIGH BEAM HEADLAMP IS INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Due to the varying wattage ratings and resulting current draw of certain aftermarket headlamp bulbs, the SJB may activate its short circuit protection strategy, resulting in the low beam output circuit becoming inoperative. Make sure that the bulbs meet Ford specifications. If the bulbs do not meet Ford specifications, install the correct bulbs. Run the on-demand self-test (required to clear certain DTCs and reset the SJB). Correct any unresolved DTCs. Clear all DTCs. Test the system for normal operation.
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C1 CHECK THE LOW BEAMS
- NOTE: Make sure the multifunction switch is in the LOW BEAM position.
- Place the headlamp switch in the HEADLAMPS ON position.
- Is the low beam in the headlamp in question illuminated?
Yes
GO to C2.
No
Go To Pinpoint Test B. Pinpoint Test B: One Low Beam Headlamp Is Inoperative
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C2 CHECK THE RECORDED DTCs FROM THE SJB SELF-TEST
- Place the headlamp switch in the OFF position.
- Check the recorded results from the SJB self-test.
- Is DTC B1570 recorded?
Yes
GO to C3.
No
GO to C4.
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C3 CHECK CIRCUIT CLF02 (GY/BN) (LH HEADLAMP) OR CIRCUIT CLF03 (VT/OG) (RH HEADLAMP) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Inoperative Headlamp.
- Disconnect: SJB C2280e.
- Measure the resistance between the inoperative rear lamp, harness side and ground as follows:
- Is the resistance greater than 10,000 ohms?
Yes
GO to C5.
No
REPAIR the circuit in question. RUN the on-demand self-test (required to clear certain DTCs). CORRECT any unresolved DTCs. CLEAR all DTCs. TEST the system for normal operation.
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C4 CHECK CIRCUIT CLF02 (GY/BN) (LH HEADLAMP) OR CIRCUIT CLF03 (VT/OG) (RH HEADLAMP) FOR AN OPEN
- Ignition OFF.
- Disconnect: Inoperative Headlamp.
- Disconnect: SJB C2280e.
- If the LH high beam is inoperative, measure the resistance between the LH headlamp C1284-3 or C1021-1, circuit CLF02 (GY/BN), harness side and the SJB C2280e-16, CLF02 (GY/BN), harness side.
- If the RH high beam is inoperative, measure the resistance between the RH headlamp C1285-3 or C1041-1, circuit CLF03 (VT/OG), harness side and the SJB C2280e-30, CLF03 (VT/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to C5.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
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C5 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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