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I have been having some problems with the AEM Series 2 EMS, and I've tuned some manual Supras and s2000's with it in the past. But I always have the same problem with the map sensor. If I choose a stock mapsensor and turn the ignition on I could get like 45 kPa, like on the picture. I've also tried with serveral aftermarket sensors that's on their list but it is always skewed up values. So I end up choosing a gm 3 bar or something just to get around 100 kPa when ignition on. And i really hate it, because it's not the right way to do it, as you know. Have you experienced something similar or am I doing something wrong? It's really just an easy choice in a list of sensors. What could I do wrong?
I also have some customers that really want to keep their auto transmission in their Supra MK IV's. And I wonder if anyone here has tried the AEM V2 plugin for Supra 93-98, that also handles the auto transmission. And if you have any tips or starting points on how to start Tuning the parameters and tables for the auto transmission. I was looking at the new infinity series but saw that they had no option for auto trans in those.
Thank you for your time. Looking forward to some great replies.
Best Regards Jim @ Jim's Tuning, Sweden.
I spent several days tuning a AEM v2 on an automatic Supra. I really recommend to leave your hands away from it. The automatic transmission shifts horrible and shift strategy is very bad, too. AEM doesn't support automatic transmission anymore! I suppose they had just too many unsatisfied customers.
The automatic control is very basic and only good for drag use. It lacks alot of functionality. For example if you adjust shift solenoids for smooth upshift, downshifts are really hard and vica verca. I'm sure the OEM ECU controlls the shift solenoids different during up an downshifts. AEM lacks this strategy. In manual mode the clutch does not open when you come to a stop, consequently the engine stalls.
There is also a bug, shift ign retard does not work when you shift from zero to first, which feels pretty rough.
Besides i don't like AEM v1 and v2 at all, there is no 3D IAT correction table, so you never get your AFR's right arround idle when it heat sucks.
Here is a thread, people seems to have the same problems with AT control.
The stock automatic transmission control works quite good. I would wire in a LINK ecu for Engine control and leave all AT stuff on the OEM ECU.
Thanks for the great info. Seems like it's best to stay away from it. How do you keep the OEM ECU for just the transmission and still wire in a aftermarket ecu? Wouldn't there be a lot of error codes that would interrupt with the transmission control, or are they fairly separate to each other? There are many people with auto Supras out there, wonder how the solved the problem the best way. Keep the good answers coming.
Pretty sure most of them did it like Adrian said. Wired in another ECU for engine control and left the stock ECU for controlling the automatic transmission.