The ECU detects the current gear/speed according to the output signals from the
input and output shaft speed sensor.
DIAGNOSIS CODE SET CONDITIONS
If the output shaft speed sensor output value, which is multiplied by the
gear ratio, deviates from the input shaft speed sensor output value by a predetermined range
or more after the gear shifting, diagnosis code No. P0777 is set.
If the output shaft speed sensor output value, which is multiplied by the gear ratio,
deviates from the input shaft speed sensor output value by a predetermined range or less before
the gear shifting, diagnosis code No. P0777 is set.
PROBABLE CAUSES
Damaged harness wires and connectors
Malfunction of the A/T-ECU
Malfunction of solenoid valve
Malfunction of the valve body assembly
Malfunction of the transmission assembly
Malfunction of the pressure control solenoid SL1 system (for diagnosis codes No.
P0965, P0966, P0967)
Malfunction of the shift solenoid SR system (for diagnosis codes No. P0973, P0974)
Malfunction of the shift solenoid SB system (for diagnosis codes No. P0976, P0977)
DIAGNOSIS PROCEDURE
STEP 1. Solenoid check
Check the pressure control solenoid SL1 and the shift solenoid SR, SB.
Q.
Is the check result normal?
Go to Step 2.
Replace the valve body assembly.
STEP 2. Check whether the diagnosis code is set again.
(1)Erase the set diagnosis code.
(2)Turn the ignition switch to the "LOCK" (OFF) position.
(3)Turn the ignition switch to the "ON" position.
(4)Check again if the diagnosis code is set.
Q.
Is diagnosis code No. P0777 set?
Replace the valve body assembly or the transmission assembly.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent
Malfunction).