Circuit Description

WARNING: This page is about a different car, the 2004 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.

The vehicle equipped with ABS detects a vehicle speed using the stability control ECU and wheel speed sensor. This sensor monitors a wheel rotation speed and sends the signal to the ECU.

The stability control ECU converts these wheel speed signals into a 4-pulse signal and outputs it to the ECM via the combination meter.

The ECM determines the vehicle speed based on the frequency of these pulse signals.

In the vehicle without ABS, the No. 1 vehicle speed sensor outputs a 4-pulse signal for every revolution of the rotor shaft, which is rotated by the transmission output shaft via the driven gear. After this signal is converted into a more precise rectangular waveform by the waveform shaping circuit inside the combination meter, it is then transmitted to the ECM. The ECM determines the vehicle speed based on the frequency of these pulse signal.

w/ ABS:

Fig 1: Identifying Vehicle Speed Sensor (w/ ABS) - Circuit Description

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

w/o ABS:

Fig 2: Identifying Vehicle Speed Sensor (w/o ABS) - Circuit Description

DTC DETECTION CONDITION

DTC No.	DTC Detection Condition	Trouble Area
P0500	The ECM detects following conditions simultaneously 500 times (2 trip detection logic): No SP1 (speed sensor) signal while ECM detects SP2 (No. 2 speed sensor) signal Vehicle speed is 6 mph (9 km/h) or more for 4 seconds Park/Neutral position switch is OFF (Shift lever is in other than P and N positions) Transfer is in other than N position	Open or short in speed sensor circuit Speed sensor Combination meter ECM Stability control ECU