Circuit Description
Shifting from 1st to O/D is performed in combination with ON and OFF of the shift solenoid valves No. 1 and No. 2 controlled by the ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valve in order to allow the vehicle to be operated safely (Fail-safe function).
Fail-safe Function:
If either of the shift solenoid valve circuits develops an open or short, the ECM turns the other shift solenoid ON and OFF in order to shift to the gear positions shown in the table below. The ECM also turns the shift solenoid valve SL OFF at the same time. If both solenoids are malfunctioning, hydraulic control cannot be performed electrically but must be done manually. Manual shifting must be performed as shown in the following table (in the case of a short circuit, the ECM stops sending current to the short circuited solenoid).