Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Possible Causes
2021 Ford Edge SE, 4WDSECTION Possible Causes
WARNING: This page is about a different car, the 2019 Ford F-550 Super Duty, 2019 Ford F-450 Super Duty, 2019 Ford F-350 Super Duty, and 2019 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
- 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.
- 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. - 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. - Measure the resistance between:
- 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. - Measure the resistance between:
- 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 Connector Repair Procedures article for schematic and connector information.Install a new brake lining wear indicator or indicators as necessary. REFER to the Service Information. - Measure the resistance between:
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.