TCU Status¶

Terminology¶

First we need to establish good terminology.

Transmission Control Module¶

Let's agree that control is applicable only if you are toggling transmission solenoids. TCU could be external or internal to bellhousing, but either way - TCU is wired directly to transmission solenoids. Ford, Toyota and Honda love combining TCU and ECU, those should be called PCM (powertrain control module)

CANbus gateway¶

Let's agree that a separate device which sits between ECU and TCU is a CANbus gateway.

build-in CANbus integration¶

Some ECUs can talk to TCUs over CANbus or legacy signal wires. We plan to add direct CANbus TCU integration into new future Premium closed source rusEFI binaries at some point later.

rusEFI has basic TCU logic¶

A Ford 4R70W has driven under rusEFI TCU control.

We have code for GM 4Lxx transmissions, but zero or very little real life testing. We also have an alternative Lua firmware for direct control of older transmissions.

Modern Stuff¶

We have purple Gateway compatible with a couple of different modern GM transmissions.

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!