DementedEM2

Okay, im completely new to the honda world and i have an EM2 its an 03 Civic EX with the stock D17A2 and auto tranny. A few months ago the tranny went out so it had been sitting there till i had went and picked up a 01 EM2 four door ex with same motor and tranny and i did a swap over all together to get my car running, and when i swapped it over got it all plugged in and wired up right it started just fine but my check engne light is now on, i believe if the D on the cluster for the tranny is blinking its a tranny error, and the engine is idling up and down on its own. So i had a few questions:
what the transmission error could be if the D is blinking on the cluster?

Why the engine is idling up and down on its own?

If i have to move over ECM out the 01 to my 03?

Last question,
If i have to move over wiring harnesses?

If you have anny suggestions they would be much appreciated.

BlueEM2

iTrader: (1)

You shouldn't need the ECU, they are interchangeable... Blinking D is a tranny error yes but you need to get the code checked to know what it is for sure... The up/down idle could a whole bunch of stuff. Throttle body related, take the TB off your old engine if it worked fine and swap it over to the new one. Wire harness should be interchangeable but there are others that know more about this stuff than I do.

DementedEM2

Thanks tbohar, im gonna go ahead and swap the tb over and see what that does. And try and look up the code for the transmission.