DTC P0731 Gear 1 Incorrect Ratio: DTC Detecting Condition

DTC DESCRIPTION REFERENCE

Item	Detecting Condition	Possible cause
DTC Strategy	1st gear incorrect ratio	Faulty Input speed sensor Faulty output speed sensor Faulty UD clutch or LR, RED brake or One way clutch 1,2
Enable Conditions	Engine speed > 450 rpm Output speed > 150 rpm Shift stage 1st. gear Input speed > 0 rpm A/T oil temp output ≥ -23°C (-9.4°F) 11V ≤ Battery Voltage ≤ 16V TRANSAXLE RANGE SWITCH is normal and after 2 sec is passed from IG ON
Threshold value	\| input speed - output speed x 1st gear ratio \| ≥ 200 rpm
Diagnostic Time	More than 4 sec
Fail Safe	Locked into 3rd gear