DTC 42

DTC 42 VEHICLE SPEED SENSOR CIRCUIT






CIRCUIT DESCRIPTION






The vehicle speed sensor outputs a 4-pulse signal for every revolution of the transaxle differential. This signal is then converted into a more precise rectangular waveform by the waveform shaping circuit inside the combination meter, and transmitted to the ECM.

Fail Safe Function
If the vehicle speed sensor fails, shift control takes place so that the throttle opening ratio and RPM are controlled according to the shift control map.




A Zone: Shift down 2 gears
B Zone: Shift down 1 gear
C Zone: No change
D Zone: Shift up 1 gear
E Zone: Shift up 2 gears
F Zone: Shift up 3 gears

WIRING DIAGRAM





INSPECTION USING AN OSCILLOSCOPE

Waveform between terminals SPD and E1 when vehicle speed is approx. 20km/h (12mph).The greater the vehicle speed, the greater the number of SPD signals produced.:

INSPECTION PROCEDURE