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 circuits CLF04 (BN/BU) and CLF05 (BU/GN) to the LH and RH low beam headlamps. Ground is supplied through circuits GD120 (BK/GN) and GD123 (BK/GY) to the LH and RH headlamps.
B2A2E-B2A31:
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Headlamp assembly
- 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 resulting current draw of certain aftermarket headlamp bulbs, the SJB 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. 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.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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B1 USE THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check the recorded results from the SJB self-test.
- Is DTC B2A2F or B2A31 recorded?
Yes
GO to B5.
No
GO to B2.
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B2 CHECK THE HEADLAMP VOLTAGE SUPPLY CIRCUIT FOR VOLTAGE
- Ignition OFF.
- Disconnect: Inoperative Headlamp.
- Place the headlamp switch in the HEADLAMPS ON position.
- For Sable or Taurus X, measure the voltage between the LH headlamp C1111-A, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1112-A, circuit CLF05 (BU/GN), harness side and ground.
- For Taurus, measure the voltage between the LH headlamp C1284-6, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1285-6, circuit CLF05 (BU/GN), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
For Sable or Taurus X, REPAIR the ground circuit in question for an open. CLEAR the DTCs. REPEAT the self-test.
For Taurus, GO to B3.
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.
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B3 CHECK THE HEADLAMP GROUND CIRCUIT FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the LH headlamp C1284-4, circuit GD120 (BK/GN), harness side and ground; or between the RH headlamp C1285-4, circuit GD123 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
REPAIR or INSTALL a new headlamp assembly. REFER to Headlamp Assembly Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR the ground circuit in question. CLEAR the DTCs. REPEAT the self-test.
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B4 CHECK THE HEADLAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Disconnect: SJB C2280e.
- For Sable or Taurus X, measure the resistance between the LH headlamp C1111-A, circuit CLF04 (BN/BU), harness side and the SJB C2280e-13, circuit CLF04 (BN/BU), harness side; or between the RH headlamp C1112-A, circuit CLF05 (BU/GN), harness side and the SJB C2280e-4, circuit CLF05 (BU/GN), harness side.
- For Taurus, measure the resistance between the LH headlamp C1284-6, circuit CLF04 (BN/BU), harness side and the SJB C2280e-13, circuit CLF04 (BN/BU), harness side; or between the RH headlamp C1285-6, 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 B8.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
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B5 ISOLATE THE BULB AS THE CAUSE OF THE SHORT TO GROUND DTC
- Disconnect: Inoperative Headlamp Bulb.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Repeat the SJB on-demand self-test.
- Is DTC B2A2E or B2A30 present?
Yes
INSTALL a new headlamp bulb. REFER to Headlamp Bulb Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
For Taurus GO to B6.
For Sable or Taurus X, GO to B7.
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B6 CHECK HEADLAMP ASSEMBLY FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: Inoperative Headlamp.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Repeat the SJB on-demand self-test.
- Is on-demand DTC B2A2F or B2A31 retrieved again?
Yes
GO to B7.
No
REPAIR or INSTALL a new headlamp assembly. REFER to Headlamp Assembly Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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B7 CHECK THE SJB LOW BEAM OUTPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280e.
- Disconnect: Inoperative Headlamp.
- For Sable or Taurus X, measure the resistance between the LH headlamp C1111-A, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1112-A, circuit CLF05 (BU/GN), harness side and ground.
- For Taurus, measure the resistance between the LH headlamp C1284-6, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1285-6, circuit CLF05 (BU/GN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to B8.
No
REPAIR circuit CLF04 (BN/BU) (LH headlamp) or circuit CLF05 (BU/GN) (RH headlamp) for a short to ground. 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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B8 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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