Vehicle Speed Sensor Signal Circuit - Toyota 3VZ–FE Troubleshooting Manual

EG–396
DTC 42
CIRCUIT DESCRIPTION
The No.1 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 wave-
form 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 signals.
Code No. Diagnostic Trouble Code Detecting Condition
For Electronic Controlled Transmission
All conditions below are detected continuously for 8
sec. or more.
(a) Vehicle speed signal: 0 km/h (mph)
(b) Engine speed: 3,000 rpm or more
(c) Park/Neutral position switch (PNP) OFF
For M/T
45
All conditions below are detected continuously for 8
sec. or more.
(a) Vehicle speed signal: 0 km/h (mph)
(b) Engine speed: Between 3,000  4,500 rpm
(c) Engine coolant temp.: 80C (176F) or more
(d) Load driving
ENGINE TROUBLESHOOTING

Vehicle Speed Sensor Signal Circuit

– CIRCUIT INSPECTION

No. 1 speed sensor

Combination meter
Combination meter

Open or short in No. 1 speed sensor circuit

ECM
Trouble Area