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 to the LH and RH low beam headlamps.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Headlamp assembly (MKX)
- 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. Clear the DTCs and run the on-demand self-test (required to reset the SJB). Correct any unresolved DTCs. Test the system for normal operation.
-------------------------------------------------
B1 USE THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check the recorded results from the SJB self-test.
- Is DTCs B2A2E or DTC B2A30 present?
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 B5.
If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short. After the repair:
If no DTCs are present, TEST the system for normal operation. Diagrams By Number
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.
-------------------------------------------------
B2 CHECK FOR VOLTAGE TO THE HEADLAMP
- Ignition OFF.
- Disconnect: Inoperative Headlamp.
- Place the headlamp switch in the HEADLAMPS ON position.
- Measure the voltage between the inoperative headlamp, harness side and ground as follows:
- Is the voltage greater than 10 volts?
Yes
For Edge, REPAIR the ground circuit in question for an open. CLEAR the DTCs. REPEAT the self-test.
For MKX, GO to B3.
No
GO to B4.
-------------------------------------------------
B3 CHECK FOR VOLTAGE TO THE HEADLAMP USING THE CONNECTOR GROUND
- Measure the voltage between the inoperative LH front headlamp C1021a-1, circuit CLF04 (BN/BU), harness side and the LH front headlamp C1021a-2, circuit GD120 (BK/GN), harness side; or between the inoperative LH front headlamp C1041a-1, circuit CLF05 (BU/GN), harness side and the LH front headlamp C1041a-2, circuit GD123 (BK/GY), harness side.
- Is the voltage greater than 10 volts?
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 for an open. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
B4 CHECK THE SJB HEADLAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Disconnect: SJB C2280e.
- Measure the resistance between the inoperative headlamp, harness side and the SJB as follows:
- Is the resistance less than 5 ohms?
Yes
GO to B8.
No
REPAIR the circuit in question for an open. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
B5 ISOLATE THE CAUSE OF THE SHORT
- Disconnect: Inoperative Headlamp.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Clear the DTCs and repeat the 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 inoperative headlamp, harness side and ground as follows:
- Is the voltage greater than 10 volts?
Yes
For MKX, GO to B6.
For Edge, INSTALL a new headlamp bulb. REFER to Headlamp Bulb Service and Repair. TEST the system for normal operation.
No
GO to B7.
-------------------------------------------------
B6 CHECK THE HEADLAMP BULB
- Ignition OFF.
- Place the headlamp switch in the OFF position.
- Connect: Inoperative Headlamp.
- Install a known good headlamp bulb.
- Place the headlamp switch in the HEADLAMPS ON position.
- Does the headlamp in question illuminate?
Yes
REMOVE the known good headlamp bulb. INSTALL a new headlamp bulb. REFER to Headlamp Bulb Service and Repair. TEST the system for normal operation.
No
REMOVE the known good headlamp bulb. INSTALL a new headlamp assembly. REFER to Headlamp Assembly Service and Repair. 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.
-------------------------------------------------
B7 CHECK THE SJB LOW BEAM OUTPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280e.
- Measure the resistance between the inoperative headlamp, harness side and ground as follows:
- Is the resistance greater than 10,000 ohms?
Yes
GO to B8.
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. REFER to Body Control Systems. TEST the system for normal operation.
-------------------------------------------------
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. 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.
-------------------------------------------------