pettyboy69

iTrader: (2)

Ok so I'm looking at picking up a civic shell that has a messed up auto trans in it, and when I started searching online for used trans the dx and ex auto come up as different all together. My questions is since I am swapping the transmission will either of the options listed above, ex vtec or dx non vtec, bolt up and function just fine in the car? I know that the bolt pattern between the 2 is obviously the same since its a d series trans, but is the wiring, ecu, and shift cable all going to function properly on either trans?

thanks in advance

jbpnoman

No. The TCU is integrated into the ECU, and the DX and EX transmissions have different ratios. If you run an EX transmission on a EX ECU, you'll throw codes for the transmission, and if you swap to an EX ECU/TCU, you'll throw a CEL because the DX motor won't have a vtec solenoid.

You need to properly match the transmission to the motor for an automatic.

pettyboy69

iTrader: (2)

Ok so if I throw an ex auto trans into this dx auto car on the dx auto ecu it will throw codes for the transmission even though its all automatic?

TripleLude

Kind of like a speed-sensor or shift timing issue?

doctorake

Everything has to match.

ewilliams1990

I'm interested in this. If you have a ex car and throw in a non-ex tranny, what will have to be done in order to stop codes from being thrown? Thanks!

Chriser0

Put in a non ex ECU and A non ex motor

ewilliams1990

You'd have to swap motor to use a non-ex tranny? Maybe that is whats causing my tranny issue. It's jumping from 1st to 2nd gear. Maybe the tranny isn't matched correctly. What codes could be thrown?

Chriser0

A non ex motor (D16y7) on an ex (D16y8 (VTEC)) trans and ecu would throw a VTEC code and I believe a knock sensor code. A Y8 motor with a Y7 trans and ecu would think it was slipping and set a D4 code. same with a Y7 motor with Y8 trans. Atleast that what i had been told

orionhunts

Im in the middle of the same problem . I have a 1997 dx with a bad auto trans . I have a 1993 dx auto trans from a swap yrs ago with low mileage but Im trying to figure out if I can make it work .

ifIexplode

No you don't. All 96-98 auto transmissions are the same regardless of trim EX/DX ect. Same with 99-00. Its not like a manual transmission. A P2Pand P2E AUTOMATIC ECU's will be fine on any Auto trans.

jbpnoman

Would you like me to prove you wrong with real world experience, or with factual part numbers? I can do either, take your pick.

ifIexplode

Anyone can look up part numbers on majestic honda. Ive had EX and DX Auto transmissions apart and they are geared the same. So I choose real word experience.

jbpnoman

The differential is the same, and some gears are the same, but the majority of countershaft and mainshaft gears are different. If you don't believe the part numbers, turn your FSM to page 3-21. I'll even highlight the differences for you.

Automatic gear ratios:

D16Y7:

1 - 2.600
2 - 1.468
3 - 0.926
4 - 0.638
R - 1.954
FD - 4.357

D16Y8:

1 - 2.722
2 - 1.516
3 - 0.975
4 - 0.638
R - 1.954
FD - 4.357

If you don't believe me, open up your FSM and look for yourself. I'm not pulling these numbers out of my ***, or off some random website.

Bolt a DX auto to an EX, and you'll throw a code for the lockup solenoid because of an imaginary "slip". TCU is integrated into the ECU, so if you swap the ECU to deal with the lockup solenoid code, your car won't run right due to injector size differences, and you'll throw a code for the lack of a vtec solenoid.

Bolt an EX auto to a DX, and you'll throw a code for the lockup solenoid. Once again, integrated TCU, so swap the ECU and the same thing will happen as above.