The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 4th gear ratio, while the transaxle is engaged in the 4th gear. For example, if the output speed is 1,000 rpm and the 4th gear ratio is 0.712, then the input speed is 712 rpm.
This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 4th gear ratio, while the transaxle is engaged in 4th gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfuctioning rather than an electrical issue.
Item
Detecting Condition
Possible Cause
DTC Strategy
4th gear incorrect ratio
Faulty Input speed sensor
Faulty output speed sensor
Faulty UD clutch or 2nd brake
Enable Conditions
Engine speed >400rpm
Output speed >900rpm
Lever position : D
Input speed >300rpm
A/T oil temp output = -10°C
TRANSAXLE RANGE SWITCH is normal and after 2sec is passed from IG ON
Threshold Value
?Input speed/4th gear ratio - output speed ?=200rpm
Diagnostic Time
More than 1sec
Fail Safe
Locked into 3 rd gear.(If diagnosis code P0734 is output four times, the transaxle is locked into 3rd gear)
A : INPUT SPEED SENSOR
B : OUTPUT SPEED SENSOR