Electronic transmission control unit (ETCU) device
The ECU is the main electronic component of an automatic transmission (AT). It is responsible for controlling all aspects of the transmission, including gear shifting, torque control and torque converter lock-up control.
Main components of the ECU:
* Microprocessor: Performs control operations and makes decisions.
*ROM (Read Only Memory): Contains the software that controls the transmission.
*RAM (Random Access Memory): Stores temporary data used by the microprocessor.
* Sensors and switches: Receive information about the condition of the transmission, engine and vehicle.
* Solenoids: Control the flow of fluid into the automatic transmission to change gears and lock up the torque converter.
* Connectors: Provide communication with other electronic modules and vehicle systems.
ECU functions:
* Gear Shift Control: The microprocessor uses sensor readings to determine the optimal gear shift point, selecting the desired gear from the available ones.
*Torque Control: The ECU regulates the flow of fluid through the torque converter to control the amount of torque sent to the transmission.
* Torque converter lock-up control: The ECU locks the torque converter when enough torque is being transmitted, reducing energy loss.
* Adaptation: The computer adapts to driving conditions and component wear by adjusting shift points and setting operating parameters accordingly.
* Self-diagnosis: The ECU continuously monitors transmission operation, detects malfunctions, and sets appropriate diagnostic trouble codes (DTCs).
Additionally:
The ECM is often integrated with the engine control unit (ECM) or other electronic modules in the vehicle to coordinate transmission and engine control.