Input speed sensor value must be equal Output speed sensor value times each gear ratio at each gear position of trasmission. That operation value equal with TCM operation value. For example Output speed sensor value is 1000RPM and 1st speed gear ratio is 4.7 then Input speed sensor value must be 4700 RPM.
This code is set when Input speed sensor value is different with TCM operation value, caused by control valve sticking, solenoid valve fault(most of fault is mechanical, rarely electrical fault).
Item
Detecting Condition
Possible Cause
DTC Strategy
1st gear incorrect ratio
Input speed sensor fault
Output speed sensor fault
Clutch slip in Transmission ( UD brake, L/R brake, OWC) or oil pressure controller fault
Enable Conditions
Solenoid power voltage> 10V
Oil Temperature Sensor >-10?
Time after shift changing finish > 1sec
Engine speed >400rpm
Output speed >150rpm
Input speed > 0rpm
Shift stage 1st. gear
TR switch = "D"range
Threshold value
Output speed<(input speed-200rpm)/1st. gear ratio
Detecting Time
1 sec and 4 times
Fail safe
Locked into 4th gear
Solenoid
SS-A
SS-B
OD
N-H
35R
UD
26
N-L
N,P
?
1st
2nd
3rd
4th
5th
6th
L
REV
? : Connected status
? : Connedted at Vehicle speed above 8km/h
Clutch
Brake
OD C
26 B
UD B
LR B
O.W.
P,N
R
D1
D2
D3
D4
D5
D6
? : Operated at Vehicle speed under 5km/h
Fig 1) "D" range 1st gear