Pinpoint Test A: One Or Both Low Beams Are Inoperative

WARNING: This page is about a different car, the 2013 Ford F-150. 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 self-test (required to clear certain DTCs and reset the BCM). Correct any unresolved DTCs. Clear all DTCs. Test the system for normal operation.

A1 CHECK FOR VOLTAGE TO THE HEADLAMP ASSEMBLY

Ignition OFF.
Disconnect: Inoperative LH Headlamp C1021 or RH Headlamp C1041 (Halogen headlamps).
Disconnect: Inoperative LH Headlamp C1284 or RH Headlamp C1285 (HID Headlamps).
Place the headlamp switch in the headlamps on position.

For halogen headlamps, measure the voltage between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1021-1	CLF04 (BN/BU)	-	Ground
RH Headlamp
C1041-1	CLF05 (BU/GN)	-	Ground

Fig 1: Identifying Headlamp C1021 Connector Terminals (LH)

Courtesy of FORD MOTOR CO.

For HID headlamps, measure the voltage between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1284-1	CLF04 (BN/BU)	-	Ground
RH Headlamp
C1285-1	CLF05 (BU/GN)	-	Ground

Fig 2: Identifying Headlamp C1284 Connector Terminals (LH)

Courtesy of FORD MOTOR CO.

Is the voltage greater than 11 volts?

Yes : GO to A2.
No : VERIFY the BCM fuse 17 (10A) (LH low beam) or fuse 16 (10A) (RH low beam) is OK. If OK, GO to A6. If not OK, REFER to the appropriate System Wiring Diagrams to identify the possible causes of the circuit short.

A2 CHECK THE HEADLAMP ASSEMBLY GROUND CIRCUIT FOR AN OPEN

For halogen headlamps, measure the voltage between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1021-1	CLF04 (BN/BU)	C1021-2	GD120 (BK/GN)
RH Headlamp
C1041-1	CLF05 (BU/GN)	C1041-2	GD123 (BK/GY)

Fig 3: Identifying Headlamp C1021 Connector Terminals (LH)

Courtesy of FORD MOTOR CO.

For HID headlamps, measure the voltage between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1284-1	CLF04 (BN/BU)	C1284-4	GD120 (BK/GN)
RH Headlamp
C1285-1	CLF05 (BU/GN)	C1285-4	GD123 (BK/GY)

Fig 4: Identifying Headlamp C1284 Connector Terminals (LH)

Courtesy of FORD MOTOR CO.

Is the voltage greater than 11 volts?

Yes : For halogen headlamps, INSTALL a new headlamp bulb. REFER to HEADLAMP BULB - HALOGEN . For HID headlamps, GO to A3.
No : REPAIR the circuit.

A3 CHECK FOR BALLAST SUPPLY VOLTAGE TO THE HEADLAMP ASSEMBLY

Measure the voltage between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1284-2	SBB35 (BU/RD)	-	Ground
RH Headlamp
C1285-2	SBB16 (VT/RD)	-	Ground

Fig 5: Identifying Headlamp C1284 Connector Terminals (LH)

Courtesy of FORD MOTOR CO.

Is the voltage greater than 11 volts?

Yes : GO to A4.
No : VERIFY the BJB fuse 35 (20A) (LH headlamp) or fuse 16 (20A) (RH headlamp) is OK. If OK, REPAIR the affected circuit. If not OK, REFER to the appropriate System Wiring Diagrams to identify the possible causes of the circuit short.

A4 CHECK THE BALLAST
- Place the headlamp switch in the off position.
- Substitute a known good ballast.
- Place the headlamp switch in the headlamps on position.
- Does the inoperative headlamp illuminate?
- Yes : REMOVE the known good ballast. INSTALL a new ballast. REFER to BALLAST .
- No : REMOVE the known good ballast. GO to A5.
A5 CHECK THE HID BULB
- Place the headlamp switch in the off position.
- Substitute a known good HID bulb.
- Place the headlamp switch in the headlamps on position.
- Does the inoperative headlamp illuminate?
- Yes : REMOVE the known good HID bulb. INSTALL a new HID bulb. REFER to HEADLAMP BULB - HID .
- No : REMOVE the known good HID bulb. REPAIR or INSTALL a new headlamp assembly. REFER to HEADLAMP ASSEMBLY .

A6 REPEAT THE BCM SELF-TEST AND CHECK FOR VOLTAGE TO THE HEADLAMP

Place the headlamp switch in the off position.
Ignition ON.
Using a scan tool, clear the DTCs and perform the BCM self-test.
Place the headlamp switch in the headlamps on position.

For halogen headlamps, measure the voltage between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1021-1	CLF04 (BN/BU)	-	Ground
RH Headlamp
C1041-1	CLF05 (BU/GN)	-	Ground

Fig 6: Identifying Headlamp C1021 Connector Terminals (LH)

Courtesy of FORD MOTOR CO.

For HID headlamps, measure the voltage between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1284-1	CLF04 (BN/BU)	-	Ground
RH Headlamp
C1285-1	CLF05 (BU/GN)	-	Ground

Fig 7: Identifying Headlamp C1284 Connector Terminals (LH)

Courtesy of FORD MOTOR CO.

Is the voltage greater than 11 volts?

Yes : For halogen headlamps, INSTALL a new headlamp bulb. REFER to HEADLAMP BULB - HALOGEN . For HID headlamps, GO to A7.
No : GO to A8.

A7 CHECK THE HEADLAMP HARNESS
- Ignition OFF.
- Place the headlamp switch in the off position.
- Check the headlamp harness for an internal short to the ground circuit.
- Is the headlamp harness OK?
- Yes : INSTALL a new ballast. REFER to BALLAST .
- No : REPAIR or INSTALL a new headlamp assembly.
  REFER to HEADLAMP ASSEMBLY .

A8 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.

For halogen headlamps, measure the resistance between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1021-1	CLF04 (BN/BU)	-	Ground
RH Headlamp
C1041-1	CLF05 (BU/GN)	-	Ground

Fig 8: Identifying Headlamp C1021 Connector Terminals (LH)

Courtesy of FORD MOTOR CO.

For HID headlamps, measure the resistance between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1284-1	CLF04 (BN/BU)	-	Ground
RH Headlamp
C1285-1	CLF05 (BU/GN)	-	Ground

Fig 9: Identifying Headlamp C1284 Connector Terminals (LH)

Courtesy of FORD MOTOR CO.

Is the resistance greater than 10, 000 ohms?

Yes : GO to A9.
No : REPAIR the circuit.

A9 CHECK THE BCM LOW BEAM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

For halogen headlamps, measure the resistance between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1021-1	CLF04 (BN/BU)	C2280E-2	CLF04 (BN/BU)
RH Headlamp
C1041-1	CLF05 (BU/GN)	C2280E-1	CLF05 (BU/GN)

Fig 10: Checking BCM Low Beam Voltage Supply Circuit For Open (For Halogen Headlamps)

Courtesy of FORD MOTOR CO.

For HID headlamps, measure the resistance between:

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
LH Headlamp
C1284-1	CLF04 (BN/BU)	C2280E-2	CLF04 (BN/BU)
RH Headlamp
C1285-1	CLF05 (BU/GN)	C2280E-1	CLF05 (BU/GN)

Fig 11: Checking BCM Low Beam Voltage Supply Circuit For Open (For HID Headlamps)

Courtesy of FORD MOTOR CO.

Is the resistance less than 3 ohms?

Yes : GO to A10.
No : REPAIR the circuit.

A10 CHECK FOR CORRECT BCM OPERATION
- Disconnect and inspect all the 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 On-Line Automotive Service Information System (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, INSTALL a new BCM. REFER to MULTIFUNCTION ELECTRONIC MODULES .
- 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.