Pinpoint Test B: One Low Beam Headlamp Is Inoperative
Headlamps
Pinpoint Test B: One Low Beam Headlamp Is Inoperative
Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information Electrical Diagrams.
Normal Operation
When the Smart Junction Box (SJB) detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the LOW BEAM position, the SJB (Smart Junction Box) provides voltage to the LH and RH low beam headlamps.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- SJB (Smart Junction Box)
PINPOINT TEST B : ONE LOW 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 varying wattage ratings and resulting current draw of certain aftermarket headlamp bulbs, the SJB (Smart Junction Box) may activate its short circuit protection strategy, resulting in the low beam output circuit(s) becoming inoperative. Verify that the bulbs meet Ford specifications. If the bulbs do not meet Ford specifications, install the correct bulbs. Clear the DTCs and run the on-demand self-test (required to reset the SJB (Smart Junction Box)). Correct any unresolved DTCs. Test the system for normal operation.
B1 USE THE RECORDED DTCs FROM THE SJB (Smart Junction Box) SELF-TEST
- Check the recorded results from the SJB (Smart Junction Box) self-test.
Is DTC B2A2E or DTC B2A30 present?
Yes
GO to B2.
No
VERIFY the SJB (Smart Junction Box) fuse 7 (10A) (LH low beam) or fuse 8 (10A) (RH low beam) is OK. If OK, GO to B4.
If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams. After the repair:
If no DTCs are present, TEST the system for normal operation.
If DTC B106E is present, CLEAR the DTCs and REPEAT the self-test (required to enable the low beam output driver if DTC B106E is present). TEST the system for normal operation.
If DTC B106F is present, INSTALL a new SJB (Smart Junction Box). TEST the system for normal operation.
B2 CHECK FOR VOLTAGE TO THE INOPERATIVE HEADLAMP
- Ignition OFF.
- Disconnect: Inoperative Headlamp.
- Place the headlamp switch in the HEADLAMPS ON position.
- Measure the voltage between the LH headlamp C1021-1, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041-1, circuit CLF05 (BU/GN), harness side and ground.
Is the voltage greater than 10 volts?
Yes
REPAIR circuit GD120 (BK/GN) for an open. CLEAR the DTCs. REPEAT the self-test.
No
GO to B3.
B3 CHECK THE SJB (Smart Junction Box) HEADLAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Disconnect: SJB (Smart Junction Box) C2280E.
- Measure the resistance between the LH headlamp C1021-1, circuit CLF04 (BN/BU), harness side and the SJB (Smart Junction Box) C2280E-13, circuit CLF04 (BN/BU), harness side; or between the RH headlamp C1041-1, circuit CLF05 (BU/GN), harness side and the SJB (Smart Junction Box) C2280E-4, circuit CLF05 (BU/GN), harness side.
Is the resistance less than 5 ohms?
Yes
GO to B5.
No
REPAIR circuit CLF04 (BN/BU) (LH headlamp) or circuit CLF05 (BU/GN) (RH headlamp) for an open. CLEAR the DTCs. REPEAT the self-test.
B4 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE TO THE HEADLAMP
- Ignition OFF.
- Disconnect: Inoperative Headlamp.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB (Smart Junction Box) Self-Test.
- Clear the DTCs and repeat the on-demand self-test (required to enable the low beam output driver if DTC B106E is present).
- Place the headlamp switch in the HEADLAMPS ON position.
- Measure the voltage between the LH headlamp C1021-1, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041-1, circuit CLF05 (BU/GN), harness side and ground.
Is the voltage greater than 10 volts?
Yes
INSTALL a new headlamp bulb. REFER to Headlamp Bulb . TEST the system for normal operation.
No
GO to B5.
B5 CHECK THE SJB (Smart Junction Box) LOW BEAM OUTPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB (Smart Junction Box) C2280E.
- Measure the resistance between the LH headlamp C1021-1, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041-1, circuit CLF05 (BU/GN), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to B6.
No
REPAIR circuit CLF04 (BN/BU) (LH low beam) in question for a short to ground. After the repair:
If no DTCs are present, TEST the system for normal operation.
If DTC B106E is present, CLEAR the DTCs and REPEAT the self-test (required to enable the low beam output driver if DTC B106E is present). TEST the system for normal operation.
If DTC B106F is present, INSTALL a new SJB (Smart Junction Box). TEST the system for normal operation.
B6 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.