Speed Sensors: Notes
Speed sensors (impulse transmitters) are mounted behind each front wheel assembly, transmitting individual wheel speed information to ECU. An additional sensor is mounted to rear differential assembly to monitor rear wheel speed. The speed sensors consist of a magnetic core surrounded by coil windings. This pick-up coil is surrounded by a magnetic field. As wheel turns, teeth of a pulse wheel move through this magnetic field. This changes polarity of magnetic field and induces an alternating voltage in coil. This alternating voltage changes frequency according to wheel speed and can be used by ECU to measure wheel speed.