DTC P0500 Vehicle Speed Sensor "A": Description

With ABS:

Vehicles, which are equipped with ABS (Anti-Lock Brake System), detect the vehicle speed using the skid control ECU and wheel speed sensor. The wheel speed sensor monitors the wheel rotation speed and sends a signal to the skid control ECU. The skid control ECU converts the wheel speed signal into a 4-pulse signal and transmits it to the ECM via the combination meter. The ECM determines the vehicle speed based on the frequency of the pulse signal.

Fig 1: Vehicle Speed Sensor Pulse Signal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Without ABS:

Vehicles, which are not equipped with ABS, detect the vehicle speed using the No. 1 vehicle speed sensor. The No. 1 vehicle speed sensor transmits a 4-pulse signal for every revolution of the rotor shaft, which is rotated by the transaxle output shaft via the driven gear. The 4-pulse signal is converted into a more precise rectangular waveform by the waveform shaping circuit inside the combination meter. The signal is then transmitted to the ECM. The ECM determines the vehicle speed based on the frequency of the pulse signal.

Fig 2: Vehicle Speed Sensor Pulse Signal Without ABS

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002