Pinpoint Test A: One Or Both Low Beams Are Inoperative
Headlamps
Pinpoint Test A: One Or Both Low Beams Are Inoperative
Refer to Wiring Diagram Set 85, Headlamps/Autolamps for schematic and connector information Electrical Diagrams.
Normal Operation
When the Body Control Module (BCM) receives a message indicating a request for the headlamps, the BCM (Body Control Module) provides voltage through the headlamp output circuits to the low beams.
On vehicles equipped with halogen headlamps, voltage is sent directly to the headlamp bulbs.
On vehicles with High Intensity Discharge (HID) headlamps, voltage is sent to the ballasts. The ballasts also receive voltage at all times from the Battery Junction Box (BJB). The ballasts provide high voltage to the HID (High Intensity Discharge) bulbs when voltage from the BCM (Body Control Module) is detected.
The BCM (Body Control Module) also provides an overload protection of the low beam output circuits. When an excessive current draw is detected, the BCM (Body Control Module) disables the affected low beam circuit driver.
This pinpoint test is intended to diagnose the following:
- Fuse
- Bulb
- Wiring, terminals or connectors
- Ballast
- Headlamp assembly
- BCM (Body Control Module)
PINPOINT TEST A : ONE OR BOTH LOW BEAMS ARE 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 halogen headlamp bulbs, the BCM (Body Control Module) 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 (Body Control Module)). 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 Headlamp.
- Place the headlamp switch in the HEADLAMPS ON position.
- Measure the voltage between the LH headlamp C1021A-2, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041A-2, circuit CLF05 (BN/GN), harness side and ground.
Is the voltage greater than 10 volts?
Yes
GO to A2.
No
VERIFY the BCM (Body Control Module) 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 Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams. After the repair:
If no DTCs are present, TEST the system for normal operation.
If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the low beam output driver if DTC U1000:00 is present). TEST the system for normal operation.
If DTC U3000:49 is present, INSTALL a new BCM (Body Control Module). TEST the system for normal operation.
A2 CHECK THE HEADLAMP ASSEMBLY GROUND CIRCUIT FOR AN OPEN
- Measure the voltage between the LH headlamp C1021A-2, circuit CLF04 (BN/BU), harness side and LH headlamp C1021A-7, circuit GD120 (BK/GN), harness side; or between the RH headlamp C1041A-2, circuit CLF05 (BN/GN), harness side and the RH headlamp C1041A-7, circuit GD123 (BK/GY), harness side.
Is the voltage greater than 10 volts?
Yes
On vehicles equipped with halogen headlamps, REPAIR or INSTALL a new headlamp assembly. REFER to Headlamp Assembly . TEST the system for normal operation.
On vehicles equipped with HID (High Intensity Discharge) headlamps, GO to A3.
No
REPAIR the circuit GD120 (BK/GN) (LH headlamp) or circuit GD123 (BK/GY) (RH headlamp) for an open. TEST the system for normal operation.
A3 CHECK FOR BALLAST SUPPLY VOLTAGE TO THE HEADLAMP ASSEMBLY
- Place the headlamp switch in the OFF position.
- Measure the voltage between the LH headlamp C1021A-4, circuit SBB57 (RD), harness side and ground; or between the RH headlamp C1041A-4, circuit SBB78 (BN/RD), harness side and ground.
Is the voltage greater than 10 volts?
Yes
GO to A4.
No
VERIFY the BJB (Battery Junction Box) fuse 57 (20A) (LH headlamp) or fuse 78 (20A) (RH headlamp) is OK. If OK, REPAIR the circuit SBB57 (RD) (LH headlamp) or circuit SBB78 (BN/RD) (RH headlamp) for an open. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short Electrical Diagrams.
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. TEST the system for normal operation.
No
REMOVE the known good ballast. GO to A5.
A5 CHECK THE HID (High Intensity Discharge) BULB
- Place the headlamp switch in the OFF position.
- Substitute a known good HID (High Intensity Discharge) bulb.
- Place the headlamp switch in the HEADLAMPS ON position.
Does the inoperative headlamp illuminate?
Yes
REMOVE the known good HID (High Intensity Discharge) bulb. INSTALL a new HID (High Intensity Discharge) bulb. REFER to Headlamp Bulb . TEST the system for normal operation.
No
REMOVE the known good HID (High Intensity Discharge) bulb. REPAIR or INSTALL a new headlamp assembly. REFER to Headlamp Assembly . TEST the system for normal operation.
A6 REPEAT THE ON-DEMAND SELF-TEST AND CHECK FOR VOLTAGE TO THE HEADLAMP
- Place the headlamp switch in the OFF position.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: BCM (Body Control Module) Self-Test.
- Clear the DTCs and carry out the on-demand self-test.
- Place the headlamp switch in the HEADLAMPS ON position.
- Measure the voltage between the LH headlamp C1021A-2, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041A-2, circuit CLF05 (BN/GN), harness side and ground.
Is the voltage greater than 10 volts?
Yes
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
For vehicles equipped with halogen headlamps, INSTALL a new headlamp bulb. REFER to Headlamp Bulb . TEST the system for normal operation.
For vehicles equipped with HID (High Intensity Discharge) headlamps, INSTALL a new ballast. REFER to Ballast. TEST the system for normal operation.
No
REPAIR or INSTALL a new headlamp assembly. REFER to Headlamp Assembly . TEST the system for normal operation.
A8 CHECK THE BCM (Body Control Module) LOW BEAM VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Place the headlamp switch in the OFF position.
- Disconnect: BCM (Body Control Module) C2280E.
- Measure the resistance between the LH headlamp C1021A-2, circuit CLF04 (BN/BU), harness side and ground; or between the RH headlamp C1041A-2, circuit CLF05 (BN/GN), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to A9.
No
REPAIR circuit CLF04 (BN/BU) (LH headlamp) or circuit CLF05 (BN/GN) (RH headlamp) for a short to ground. After the repair:
If no DTCs are present, TEST the system for normal operation.
If DTC U1000:00 is present, CLEAR the DTCs and REPEAT the self-test (required to enable the low beam output driver if DTC U1000:00 is present). TEST the system for normal operation.
If DTC U3000:49 is present, INSTALL a new BCM (Body Control Module). TEST the system for normal operation.
A9 CHECK THE BCM (Body Control Module) LOW BEAM VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Disconnect: BCM (Body Control Module) C2280E.
- Measure the resistance between the LH headlamp C1021A-2, circuit CLF04 (BN/BU), harness side and the BCM (Body Control Module) C2280E-2, circuit CLF04 (BN/BU), harness side; or between the RH headlamp C1041A-2, circuit CLF05 (BN/GN), harness side and the BCM (Body Control Module) C2280E-1, circuit CLF05 (BN/GN), harness side.
Is the resistance less than 5 ohms?
Yes
GO to A10.
No
REPAIR circuit CLF04 (BN/BU) (LH headlamp) or circuit CLF05 (BN/GN) (RH headlamp) for an open. TEST the system for normal operation.
A10 CHECK FOR CORRECT BCM (Body Control Module) OPERATION
- Disconnect all the BCM (Body Control Module) connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the BCM (Body Control Module) 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 BCM (Body Control Module). 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.