TCU Status¶

First we need to establish good terminology.

There are older transmissions with an external TCU, which are mostly controlled by on/off solenoids. We have some early prototype code to handle these, but development is not active as transmission control is not a priority.

A Ford 4R70W has driven under rusEFI TCU control.

We have code for GM 4Lxx transmissions, but zero real life testing.

Modern Stuff¶

Modern transmissions use clutch-to-clutch control, which means that one clutch is engaging as another is disengaging.

Some of these transmissions use an external TCU, some use a TCU built into the transmission, and some are controlled by the ECU.

For those we are focusing on CAN integration only, not looking to re-invent the TCU itself. Even if someone implements direct solenoid/actuator control, we doubt that anyone within the enthusiast realm would be able to meaningfully tune such a solution anyway. CAN bus integration with the OEM TCU is the only way for modern transmissions!