Can a 4L80E run without a computer? I have a 4L80E from a 2003 Chevy van that I want to test but I do not have the computer or wiring harness for it. Can I put it in a car and drive the car to see if it works? I know there is a gear selector lever on the side of the trans – can I drive the car if I am switching gears manually with the lever?

Thanks, -Dave

 

No you will need to find someway to control the trans. call around local trans shops and ask about a scafter shifter. Some have this and it would allow that test

 

Hmm, well I need to buy an LS1 ECM and harness anyway, and I hear that the ECM controls both the engine and the trans… could I get something where the ECM would control the transmission only… sort of in a stand-alone mode… and let me test the transmission with a simple carbed SBC?

 

Yes several companies make stand alone Controllers for these

 

Thanks.. but I don't think I want to spend a lot of money and time buying and setting up a stand alone system when I am just going to ditch it anyway. Can the stock PCM be programmed to run the 4L80E in stand-alone mode?

 

I do not know the answer to that question , You would need to ask some tuner guys about that one but I doubt it since the PCM relys on so much info from the engine to make shifts

 

Simple answer is no. Are you putting the 4L80E behind a non-ECM engine? Your best bet if so would be to either convert it to a manual setup or non-ECM setup ... or find a different trans.

To make the stock ECM work as a stand alone, you will need RPM, TPS%, MPH at least to make it function. I am not sure what other things you will need to log from the engine to have the 4L80E happy and keep the shift pressures in check.

 

I am doing a major engine/trans swap on a car I did not drive prior to the swap and I don’t want to waste valuable break-in time finding out whether or not the transmission and drivetrain are working properly. I would rather put in a regular SBC to test the transmission and drivetrain before putting in my new turbo engine… I want to get all of the driveline and suspension bugs out before I go to the tuners… but I want to run the new engine as little as possible before I get to the tuner.

 

A 4L80E can be made to run without any electronics but it has to be full manual valve body which would get old on a daily driver. Someone, I think Yank, had one for sale on here not long ago. The link below is for info only. I am not trying to help them sell anything because they aren't a sponser here.
http://www.transmissioncenter.net/4L80E.htm

 

I use a compushift standlone to shift my 4l80e. Works great. Nice display and ez to use