Transmission control unit (TCU)
Location:
*Under the hood, next to the battery
Functions:
* Gear shift control
* Monitoring transmission parameters (oil pressure, temperature, etc.)
* Fault diagnosis
* Transmission overload protection
Design:
* Electronic control unit (ECU)
* Connectors for connecting to the wiring harness
* Oil pressure, temperature and gear selector position sensors
Main faults:
* Shift errors
* Noise and vibration when shifting gears
*Transmission slipping
*Transmission fluid leak
Diagnostics and repair:
* Computer diagnostics to read fault codes
* Checking the level and condition of the transmission fluid
* Assessing the condition of sensors and connectors
* Repair or replace damaged components
Design and principle of operation:
* The ECU receives signals from transmission sensors and the engine control unit.
* Based on the data received, the ECU calculates the position of the gear selector and controls the operation of the solenoids of the hydraulic module, which changes gears.
* The ECU also monitors transmission parameters and, if a malfunction occurs, turns on the malfunction indicator and writes fault codes into memory.