The automatic transmission control unit (Transmission Control Module, TCM) for Toyota Corona ST190 is usually located on the gearbox housing or in the engine compartment. This is an electronic component responsible for controlling the operation of an automatic transmission (AT) in a car.
Location:
*Transmission Housing Mounted: Typically attached to the top or right side of the transmission housing with bolts.
*Engine Compartment: May sometimes be located in the engine compartment, mounted on the air filter housing or other suitable surface.
Determining its presence:
* Visual Inspection: Look for a small black or gray rectangular box on the transmission or engine compartment. It will usually say “TCM” or “Transmission Control”.
*Check Wiring: The automatic transmission control unit will have several electrical connectors connected to it. Follow the wires coming from the transmission to find it.
Function:
The automatic transmission control unit receives signals from various vehicle sensors, such as the throttle position sensor, speed sensor and ATF pressure sensor, to determine the optimal gear shift point. It uses these signals to control solenoids and valves in the transmission to change gears smoothly and ensure maximum operating efficiency.
Replacement:
If the automatic transmission control unit is faulty, it must be replaced. Replacing the automatic transmission control unit requires special equipment and knowledge, so it is recommended that you contact a qualified mechanic.