stenseltizm

Ok before all the typical 'just change it to manual' bullshit, I don't have an auto but know people that do and some are die-hard and won't give up the auto. Plus I've seen this topic many times but have never seen a concrete solution/answer.

I found these posts (who said google search wont work )
https://www.homemadeturbo.com/forum/...5498#msg705498

https://www.homemadeturbo.com/forum/...8370#msg878370

both reference using an auto P75 and a TCM out of an accord or prelude.

Has anyone ever done this? Any ideas walkthroughs how to wire in the TCM, or is it plug-n-go?
Thanks

Edit: I think I found some facts supporting the p75 and tcm deal, I'll try and test it out and post up if it works.

ichbinsobose

auto integras, once again, use tcms and it ran on my chipped ecu now that I think about it, before I did my swap? but it's blurry and I don't remember what I did first.

HondaTuner

What do you guys think of this; use a chipped P75 (since auto integras/accords/preludes used both the TCM and ECU unlike the civics and del sols who had the transmission controls on the ecu itself) then use a TCM from an accord/prelude/whatever? Biggest downfall I can see for this is shift points; ie, my redline on a z6 is 7200, auto integras are redlined at 6500 correct? Cant change this? Ideas ideas...

Minor Threat

I have never seen a car shift or run right trying to use a chipped auto ECU. There is something in the code itself that controls some aspect of the TCU.

And all auto OBD1 cars have TCU's, as far as I know, it's the OBD2 that have the TCU built in.

HondaTuner

Theres a part on the board that controls the 'TCM' type parts, which is removed when you chip the computer. So then there is no control for the transmission to know when its supposed to shift (I remember seeing afew people with autos with chipped ecu's who 'manually shifted' their cars).

Not all OBD1 cars have the TCM, for instance my civic is an auto, 93, and it has only the ECU. So maybe after that they started to get rid of the TCU's? That I am not sure about...

Tom-Guy

I've never actually played with a boosted automatic setup, but I do have a few interesting puzzle pieces.

90-91 Integra (I ASSume others are similar) have MAP signal sent to them. Molest the MAP, molest the TCU? I dunno. If you just shoot 3 volts to the TCU via a Hobbs switch it'll go into WOT performance mode. Just a guess.

You can raise shift points by overclocking the TCU... replace the crystal next to the MCU with a faster one.

HondaTuner

Sounds interesting

Shifting the tranny manually tonight made me feel like a ricer (since I needed to w/ chipped ecu). Tim made a neat little LED vtec light on the ecu though haha :P

stenseltizm

Thanks for the info.

i want to try out a tcu/chipped p75 on sins car in the next couple weeks. I found some pinouts over on pgmfi that should be enough to pull it off.

Yeah i notice A17 is marked ATLV (auto tranny..?) on my OBD1 pinout, guess the IAB pin is shared with the auto tranny control? My IAB test LED was on solid, hopin it's just cause it's in an auto car. I'll test it in yuriy's teg tomorrow.

Minor Threat

Apparently the OBD1 Tegs use MAP, barometric and TPS in order to learn the shift points of the car.

leed

When Jeff boosted his 4dr auto, we were pretty curious how much his chipped ECU would ---- w/ the tranny. The wierd thing is, it pretty much drives and shifts like normal, and OD lock-up works. The one low side, is it shifts too early for Jeff's liking. He prefers to fully wheeze out his D's.