Pinpoint Test B: One Low Beam Headlamp Is Inoperative
Headlamps
Pinpoint Tests
Pinpoint Test B: One Low 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 LOW BEAM position, the SJB provides voltage through the headlamp output circuit to the LH low beam headlamp and to the RH low beam headlamp.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- SJB
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 the resulting current draw differences of certain aftermarket headlamp bulbs, the SJB may activate its short circuit protection strategy, resulting in the low beam output circuit becoming inoperative. Verify 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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B1 USE THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check the recorded results from the SJB self-test.
- Was DTC B2A2E or DTC B2A30 recorded?
Yes
GO to B2.
No
VERIFY the SJB 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. Diagrams By Number
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. REFER to Body Control Systems. TEST the system for normal operation.
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B2 CHECK THE SJB HEADLAMP VOLTAGE SUPPLY CIRCUIT FOR VOLTAGE
- Ignition OFF.
- Disconnect: Inoperative Headlamp.
- Place the headlamp switch in the HEADLAMPS ON position.
- For vehicles with aero-type headlamps, measure the voltage between the LH headlamp C1284-1, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1285-1, circuit CLF05 (BU/GN), harness side and ground.
- For vehicles with sealed-beam headlamps, measure the voltage between the LH headlamp C1021-3, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041-3, circuit CLF05 (BU/GN), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
REPAIR the ground circuit in question for an open. CLEAR the DTCs. REPEAT the self-test.
No
GO to B3.
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B3 CHECK THE SJB HEADLAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Disconnect: SJB C2280e.
- For vehicles with aero-type headlamps, measure the resistance between the LH headlamp C1284-1, circuit CLF04 (BN/BU), harness side and the SJB C2280e-13, circuit CLF04 (BN/BU), harness side; or between the RH headlamp C1285-1, circuit CLF05 (BU/GN), harness side and the SJB C2280e-4, circuit CLF05 (BU/GN), harness side.
- For vehicles with sealed-beam headlamps, measure the resistance between the LH headlamp C1021-3, circuit CLF04 (BN/BU), harness side and the SJB C2280e-13, circuit CLF04 (BN/BU), harness side; or between the RH headlamp C1041-3, circuit CLF05 (BU/GN), harness side and the SJB C2280e-4, circuit CLF05 (BU/GN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to B6.
No
REPAIR the circuit in question for an open. CLEAR the DTCs. REPEAT the self-test.
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B4 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE TO THE HEADLAMP
- Ignition ON.
- Disconnect: Inoperative Headlamp.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Clear the DTCs and repeat the on-demand self-test.
- Place the headlamp switch in the HEADLAMPS ON position.
- For vehicles with aero-type headlamps, measure the voltage between the LH headlamp C1284-1, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1285-1, circuit CLF05 (BU/GN), harness side and ground.
- For vehicles with sealed-beam headlamps, measure the voltage between the LH headlamp C1021-3, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041-3, 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 Service and Repair.
No
GO to B5.
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B5 CHECK THE SJB HEADLAMP VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280e.
- Disconnect: Inoperative Headlamp.
- For vehicles with aero-type headlamps, measure the resistance between the LH headlamp C1284-1, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1285-1, circuit CLF05 (BU/GN), harness side and ground.
- For vehicles with sealed-beam headlamps, measure the resistance between the LH headlamp C1021-3, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041-3, circuit CLF05 (BU/GN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B6.
No
REPAIR the circuit 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. REFER to Body Control Systems. TEST the system for normal operation.
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B6 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. REFER to Body Control Systems. 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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