Electronic Shift Control System

COMPONENT LOCATIONS





TRANSMISSION CONTROL MODULE (TCM)
The TCM controls gear shift, TCC, etc. according to the signals from each sensor. It is a microcomputer consisting of an IC, transistor, diode, etc. It is installed at the left side of the steering column.





Throttle Position Sensor
This sensor is installed to the throttle valve shaft. Throttle valve opening signal is transmitted from TP sensor to ECM as voltage signal. The signal is converted to duty signal in ECM and it is sent to transmission control module.





Vehicle Speed Sensor
This sensor is a pulse generator type that detects revolution of the counter driven gear (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 counter driven gear rotor 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 in- putted to the TCM where TCM judges the counter driven gear revolution or the vehicle speed.





Forward Clutch Cylinder Revolution Sensor (Input shaft revolution sensor)
This sensor is a pulse generator type that detects revolution of the forward clutch drum (Input shaft) in the transmission case. The principle of operation is the same as the vehicle speed sensor but TCM detects the revolution speed inputted to the transmission based on the signal from this sensor.





Transmission Range Switch (Sensor)
Being linked with the selector lever, this switch changes selector lever positions into electric signals and send them to the transmission control module. The contact points of this switch for P and N ranges are also connected with the starting motor circuit. Also, as its contact point for R range is connected with the back up light circuit, only when the selector lever is shifted to R range, the contact point contacts to light the back up light.





Brake Switch (Stop Lamp Switch)
The same switch is used as the brake lamp switch. It disengages the TCC when the brake is depressed while the TOO is operating.





Engine Coolant Temperature Sensor (ECT Sensor)
The engine coolant temperature is detected by the engine coolant temperature sensor in engine and emission control system and sent from ECM to TCM as a signal. TCM uses this signal as one of the factors to control gear shift to the 4th (O/D) gear, TCC operation and throttle pressure.








Over-drive (O/D) Cut Switch
The gear shift up or shift down to and from the O/D gear can be selected with this switch.

Cruise Control Unit (it equipped)
Cruise control unit is also can be control the gear shift up or shift down to and from the O/D gear and TCC (lock-up) when cruise control system is operating.





Engine Speed Signal
This signal is sent from ignition primary circuit. TCM uses this signal as one of the factors to detect malfunction of TCC operation.