Tacoma & 4Runner

Vehicle speed sensor is mounted near rear of transmission or transfer case and contains a 3-pin electrical connector. See Fig 1. On Tacoma, electrical connector contains Blue, Green/Red and Pink wires. On 4Runner, electrical connector contains Black/Yellow, Pink/Blue and Gray/Blue wires.
On all models, connect voltmeter positive lead to terminal No. 3 (outer terminal) and negative lead to terminal No. 2 (center terminal) on vehicle speed sensor. See Figure, Fig 2 and Fig 3 .
Using jumper wires, connect positive battery terminal to terminal No. 1 (outer terminal) and negative battery terminal to terminal No. 2 (center terminal) on vehicle speed sensor. See Figure, Fig 2 and Fig 3 .
While rotating vehicle speed sensor shaft, ensure voltage changes from zero volts to at least 11 volts. Voltage should change 4 times per revolution of shaft. Replace vehicle speed sensor if voltage does not change as specified. Remove test equipment.

Fig 1: Locating Typical Vehicle Speed Sensor (Tacoma & 4Runner)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Testing Vehicle Speed Sensor (Tacoma 2WD With A/T & 4Runner 2WD With A/T)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 3: Testing Vehicle Speed Sensor (Tacoma 2WD With M/T & 4Runner 2WD With M/T)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002