The four wheel drive control ECU judges whether the transfer is in the L4 position based on the information from the limit switch inside the transfer shift actuator assembly which is detected by the ECM. The four wheel drive control ECU then inputs a signal to the combination meter assembly via CAN communication and turns on the 4LO indicator.

When 2nd mode is selected with the pattern select (2ND) switch, the ECM controls the solenoid valves and the transmission starts from 2nd gear.

The 2nd mode is the system that operates the throttle motor to control engine output to reduce skidding of the driving wheels, and guarantee takeoff acceleration, driving straightness and turning stability.

When the shift lever is in D, the transmission automatically shifts up through 3rd to 6th as usual.

The ECM memory contains the programs for the normal and power shift patterns and lock-up pattern.

By following the programs corresponding to the signals from the pattern select switch, the park/neutral position switch and other various sensors, the ECM switches the solenoid valves on and off, and controls the transmission gear change and the lock-up clutch operation.

When moving the shift lever to S using the transmission control switch, it is possible to switch the shift range between "1" (1st range) and "6" (6th range).

Shifting to "+" once raises the shift range by one, and shifting to "-" lowers the shift range by one.

The engine control unit and the transmission control unit are located inside the ECM. The engine control unit intercommunicates with the transmission control unit with the Controller Area Network (CAN). If there is a problem in this intercommunication, the ECM stores a DTC.

The 1-2 shift valve performs shifting to 1st gear and other gears. When shifting to 2nd and 4th gears is impossible, or when the ECM directs the transmission to switch to 5th and 6th gear and the engine overruns (clutch slips), this DTC is stored.

The ECM detects the signal from the transfer L4 position switch.

This DTC indicates that the transfer L4 position switch remains on.

Shifting from 1st to 6th is performed in combination with the ON and OFF operation of the shift solenoid valves SL1, SL2, S1, S2, S3, S4 and SR, which are controlled by the ECM. If an open or short circuit occurs in the shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be operated safely ().

The amount of current flow to the solenoid is controlled by the duty ratio* of the ECM output signal. During the lock-up operation, if the duty ratio increases, the lock-up hydraulic pressure increases.

The ECM uses the signals from the throttle position sensor, air-flow meter, turbine (input) speed sensor, output speed sensor and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.