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.
Front Wheel Speed Sensor: Description
The Mark 20e system uses two-wire wheel speed sensors, known as active wheel speed sensors. The sensors use an electronic principle known as magneto resistive to help increase performance and durability. The sensors convert wheel speed into a small digital signal. A wheel speed sensor is used at each wheel. The gear (tooth) type tone wheel serves as the trigger mechanism for each sensor. At each wheel of the vehicle there is one wheel speed sensor and one tone wheel.
The front wheel speed sensors are attached to bosses in the steering knuckles (Fig 1 ) (Fig 2 ). There is a heat shield mounted between each sensor and the knuckle. The tone wheel is an integral part of the outboard constant velocity joint located in the front axle shaft.
WSS air gaps are not adjustable. The initial factory WSS air gap specification can be found in SPECIFICATIONS . Each WSS is serviced individually. The tone wheels are serviced as part of the drive shaft.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.