Myth about transmission controllers

[Blurry94]

If you install an aftermarket EFI system, you don't necessarily have to also buy an aftermarket transmission controller. I have found that the EEC-4 ECU's only need throttle position and vehicle speed to operate the shift points, and they CAN be used as a transmission controller.

 

[rusty_408]

i was wondering about this before starting my holley project I know the mass air eec i pulled out at least needed rpm, tps, and vss. I was always wondering what the wiring diagrams looked like for the old Pro-M dual EEC mass air system looked like.

You still need to tune it, but moates is back open and has chips. efidynotuning has free strategy files.

 

[Raymond_B]

If you install an aftermarket EFI system, you don't necessarily have to also buy an aftermarket transmission controller. I have found that the EEC-4 ECU's only need throttle position and vehicle speed to operate the shift points, and they CAN be used as a transmission controller.

Can you do it? Yes, but why? You could just leave the stock PCM in place and keep the stock settings, but if you want to change something then you'll need at least a chip and someone to program it, what if you make more changes, back to paying someone for programming. Or you can get a device you can program yourself, that would be good because you'll then have some sort of data logging.

By the time you add that up you're well on your way to a good, straightforward aftermarket controller.

 

[FMOS Racing]

It needs RPM as well for WOT shifting. You'll also have to get it the transmission temperature for torque converter lockup.

The old Pro-M Mass Air conversions used that method. A splitter and a 5-speed Mustang computer ran the engine, and then split off the signals that the stock computer needed to run the transmission.

 

[Blurry94]

It actually doesn't need RPM. While the ECU has WOT shift tables that are based off of RPM, these values are set so high that the tables using vehicle speed and throttle position over ride the RPM tables because those conditions are met first. Also, torque converter lock up schedules work fine, once the transmission warms up. Basically, you keep all of the wiring in place that is utilized to control the transmission.

I used the factory ECU to control my transmission for many years, all while using FAST XFI to control the engine. I continued to use SCT tuning software to tune the transmission: adjust shift points, converter lock-up schedules, TV pressure, ect... And C-comWP for the engine.

Is this option for everyone? Maybe, maybe not. The fact that I already had tuning software and experience with tuning the transmission, is why I tried it and it worked rather well for many years.

I probably would still be using it today had it not been for some of the pins breaking off on the ECU connector from corrosion.