Possible Causes

2018 Ford F-150 XLT, 4D Pickup Extra Cab, 3.5L Eng VIN G, RWDSECTION Possible Causes
  • Wiring, terminals or connectors
  • Brake pad wear indicator
NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may cause damage to the connector.
  1. BS1: CHECK THE BCM BRAKE LINING WEAR SENSOR CIRCUIT FOR AN OPEN 
    • Ignition OFF.
    • BCM_C connector disconnected.
    • Left Front Brake Pad Wear Indicator Switch connector disconnected.
    • Left Rear Brake Pad Wear Indicator Switch connector disconnected.
    • Measure the resistance between:
      (+) BCM_C Connector, Harness Side (-) Left Rear Brake Pad Wear Indicator Switch Connector, Harness Side
      BP_WI BP_WI
    • Is the resistance less than 3 Ohm? 
      Yes No
      Go to  BS2. REPAIR the circuit.
  2. BS2: CHECK THE REAR SENSOR TO FRONT SENSOR CIRCUIT FOR AN OPEN 
    • Measure the resistance between:
      (+) Left Rear Brake Pad Wear Indicator Switch Connector, Harness Side (-) Left Rear Brake Pad Wear Indicator Switch Connector, Harness Side
      GND BP_WI
    • Is the resistance less than 3 Ohm? 
      Yes No
      Go to  BS3. REPAIR the circuit.
  3. BS3: CHECK THE FRONT SENSOR GROUND CIRCUIT FOR AN OPEN 
    • Measure the resistance between:
      (+) Left Front Brake Pad Wear Indicator Switch Connector, Harness Side (-)
      GND Ground
    • Is the resistance less than 3 Ohm? 
      Yes No
      Go to  BS4. REPAIR the circuit.
  4. BS4: CHECK THE BRAKE LINING WEAR SENSORS FOR AN OPEN 
    • Measure the resistance between:
      (+) Left Rear Brake Pad Wear Indicator Switch Connector, Component Side (-) Left Rear Brake Pad Wear Indicator Switch Connector, Component Side
      BP_WI GND
    • Measure the resistance between:
      (+) Left Front Brake Pad Wear Indicator Switch Connector, Component Side (-) Left Front Brake Pad Wear Indicator Switch Connector, Component Side
      BP_WI GND
    • Are the resistances less than 3 ohms? 
      Yes No
      The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
      INSPECT all disconnected electrical connectors for corrosion, spread terminals, pushed-out pins, damaged pins or bent pins. REPAIR as necessary. Refer to OEM GROUND DISTRIBUTION article, for schematic and connector information.
      Install a new brake lining wear indicator or indicators as necessary. REFER to Front Disc Brake article or Rear Disc Brake article.
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.