Electronic Shift Control System

ELECTRONIC SHIFT CONTROL SYSTEM



The gear ratio change in "D" or "2" range and torque converter clutch operation are controlled by Powertrain (Engine) Control Module.


Powertrain (Engine) Control Module (PCM, ECM)



The PCM (ECM) controls not only engine & emission devises but also gear shift and torque converter clutch (shift and torque converter clutch solenoids) according to the signal from each sensor.


Throttle Position Sensor



This sensor is installed to the throttle valve shaft. Throttle valve opening signal are transmitted from TP sensor to PCM (ECM) as voltage signal.


Vehicle Speed Sensor



This sensor is a pulse generator type that detects revolution of the output shaft (vehicle speed) in the transmission case. The pulse generator is a noncontact sensor consisting of a permanent magnet, coil and gears.

As the gear of the output shaft turns, the magneflux from the permanent magnet varies and a voltage of the frequency corresponding to the rotor revolution occurs in the coil. This voltage is inputted to the PCM (ECM)where PCM (ECM)judges the output shaft revolution or the vehicle speed. The vehicle speed is also detected from the speed meter.


Transmission Range Switch







The transmission range switch send selector lever position to PCM (ECM) as voltage signal.
Also, it is provided so that the engine can be started only when the shift lever is in the "P" or "N" position.


Brake Switch




The same switch is used as the brake lamp switch. It disengages the torque converter (lock-up) clutch when the brake is depressed while the torque converter (lock-up) clutch is operating.


Engine Coolant Temperature Sensor (ECT Sensor)




The coolant temperature sensor of the engine &emission control system is used and it prevents gear change to the O/D gear and lock-up when the engine coolant temperature is 30°C (86°F) or lower.


Cruise Control Module (if equipped)




The cruise control module send cruise control operating signal to PCM (ECM).

The PCM detects whether the cruise control system is operating or not and uses it as one of the signals to control the gear shift up or shift down to and from the O/D gear and torque converter clutch.


Overdrive (O/D) Cut Switch







The gear shift up or shift down to and from the O/D gear can be selected with this switch.


Transfer 4L Switch (4WD Model)




This switch detects that the 4-wheel drive low gear is engaged and prevents the gear change into O/D and lock-up.


P/N Change Switch




The gear shift timing, normal or power, can be selected by using this switch.


Camshaft Position Sensor (CMP sensor)
The camshaft position sensor sends the pulse signal to PCM (ECM).
By using this signal PCM knows the engine speed and detects the actual transmission gear ratio (input/output ratio).


Fail Safe Function
This function is provided by the safe mechanism that assures safe driveability even when the shift solenoid valve or speed sensor fails.





The table above shows the gear position in each shift under a normal/abnormal condition.


Change Mechanism




The same select pattern shift lever is used as the floor type and frequently used "N" and "D" ranges are made selectable freely.