What makes an ECU automatic...

[[HTi]Johnson]

...and what do I ground/unground to make an ECU "think" it's a manual?

 

Thanks,

Justin

[idosubaru]

depends what you're trying to do and what you're working with. what chassis are you starting with, what engine, what ECU are you trying to use? sometimes it's really simple, sometimes it's not.

[[HTi]Johnson]

I put a FT4wd tranny in my 89 RX that had a 4eat, I want the computer to go into manual tranny mode.

 

Thanks,

Justin

[idosubaru]

is there an EA82 swap thread in the USRM that might show which pin it is?

 

i've swapped ECU's between manual and automatic transmission vehicles before with zero difference in XT6's with the 4EAT/manuals. so the ECU's are interchangeable (you probably already know that).

 

from the 1988 XT (4EAT equipped) FSM, here are the automatic transmission related ECU pinouts:

 

pin 30 (BR) appears to just be a ground pin only shown for the automatic transmission on the ECU. if it's shown for the auto but not manual, maybe this is the one? cut it and it's in "manual" mode, but i'm not sure. maybe you can disrupt it to test without actually cutting?

 

pin 14 (YW) and 15 (Lg) are from the ECU to the instrument cluster - Park, etc. doubt that matters, but maybe it won't start in "Drive"? i think that's just a relay though, not the ECU.

 

pin 42 (RB) goes to the A/C cut relay and is only shown for auto trans, so if your a/c isn't working this might be the culprit.

[subiemech85]

discrimination .