PINPOINT TEST I : One Or Both Low Beams Are Inoperative

WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Due to varying wattage ratings and the resulting current draw differences of certain aftermarket halogen headlamp bulbs, the BCM may activate its short circuit protection strategy, resulting in the low beam output circuit becoming inoperative. Verify 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 BCM). Correct any unresolved DTCs. Clear all DTCs.

I1 DETERMINE IF ONE OR BOTH LOW BEAMS ARE INOPERATIVE
- Ignition ON.
- Place the headlamp switch in the HEADLAMPS position.
Are both low beams inoperative?

Yes GO to I8

No GO to I2

I2 CHECK FOR VOLTAGE TO THE HEADLAMP ASSEMBLY

Ignition OFF.

Place the headlamp switch in the OFF position.

Disconnect: Inoperative Headlamp.

Ignition ON.

Place the headlamp switch in the HEADLAMPS position.

Measure:

Headlamp-Left

Positive Lead	Measurement / Action	Negative Lead
C1021-1	Courtesy of FORD MOTOR COMPANY	Ground

Headlamp-Right

Positive Lead	Measurement / Action	Negative Lead
C1041-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes	GO to I3
No	VERIFY BCM fuse 17 (10A) (LH low beam) or fuse 16 (10A) (RH low beam) is OK. If OK, GO to I5

I3 CHECK THE HEADLAMP ASSEMBLY GROUND CIRCUIT FOR AN OPEN

Measure:

Headlamp-Left

Positive Lead	Measurement / Action	Negative Lead
C1021-1	Courtesy of FORD MOTOR COMPANY	C1021-4

Headlamp-Right

Positive Lead	Measurement / Action	Negative Lead
C1041-1	Courtesy of FORD MOTOR COMPANY	C1041-4

Is the voltage greater than 11 volts?

Yes	GO to I4
No	REPAIR the ground circuit in question.

I4 CHECK THE BULB

Ignition OFF.

Place the headlamp switch in the OFF position.

Substitute a known good low beam bulb.

Ignition ON.

Place the headlamp switch in the HEADLAMPS position.

Does the inoperative headlamp illuminate?

Yes	REMOVE the known good low beam bulb. INSTALL a new low beam bulb. Refer to Headlamp Bulb - Expedition .
No	REMOVE the known good low beam bulb. CHECK the internal headlamp harness for open or shorted circuits and damaged or pushed-out pins. If the harness is not OK, REPAIR the harness. If the harness cannot be repaired, INSTALL a new headlamp assembly. Headlamp Assembly - Expedition

I5 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE TO THE HEADLAMP

Place the headlamp switch in the OFF position.

Using a diagnostic scan tool, clear the DTCs and perform the BCM on-demand self-test.

Place the headlamp switch in the HEADLAMPS position.

Measure:

Headlamp-Left

Positive Lead	Measurement / Action	Negative Lead
C1021-1	Courtesy of FORD MOTOR COMPANY	Ground

Headlamp-Right

Positive Lead	Measurement / Action	Negative Lead
C1041-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes	CHECK the internal headlamp harness for shorted circuits and damaged pins. If the harness is not OK, REPAIR the harness. If the harness cannot be repaired, INSTALL a new headlamp assembly. Headlamp Assembly - Expedition . If the harness Is OK, INSTALL a new low beam bulb. Refer to Headlamp Bulb - Expedition .
No	GO to I6

I6 CHECK THE BCM LOW BEAM VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO GROUND

Ignition OFF.

Place the headlamp switch in the OFF position.

Disconnect: BCM C2280E .

Measure:

Headlamp-Left

Positive Lead	Measurement / Action	Negative Lead
C1021-1	Courtesy of FORD MOTOR COMPANY	Ground

Headlamp-Right

Positive Lead	Measurement / Action	Negative Lead
C1041-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes	GO to I7
No	REPAIR the circuit in question for a short to ground.

I7 CHECK THE BCM LOW BEAM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

Measure:

Headlamp-Left

Positive Lead	Measurement / Action	Negative Lead
C1021-1	Courtesy of FORD MOTOR COMPANY	C2280E-2

Headlamp-Right

Positive Lead	Measurement / Action	Negative Lead
C1041-1	Courtesy of FORD MOTOR COMPANY	C2280E-1

Is the resistance less than 3 ohms?

Yes	GO to I8
No	REPAIR the circuit.

I8 CHECK FOR CORRECT BCM OPERATION

Disconnect and inspect all BCM connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the BCM connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSBs address this concern, BCM Hardware Testing .
No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.