Yansi

Hello all. New to the forum. I have an 03 accord EX MT with an 06 accord engine swap. Car runs good and everything is smooth until I turn on the A/C. The car drops RPMs and starts to shake uncontrollably. It still blows cold air while running but I notice power lost as the RPMS get lower.
I've checked the motor mounts
I've cleaned the throttle body
I've changed the IACV
Nothing has changed . Now my mechanic believes it is the ECU. I am taking my car in on monday to do another diagnostic.
*My question to you guys is, Does the ECU differ from 03 to 06? I believe the engines are a bit different from what I've read. Even If they are different, does it affect the A/C? Sorry for my first post being a new thread. I've tried searching and come up with the obvious. Hope You guys can help. Thanks in advance

DCFIVER

'06 and up(possibly '05 as well) are drive by wire systems, so yes the ECUs would be different. Did you swap the whole intake manifold or just the throttle body between engines?? Are there any pending codes?

Yansi

Thanks for the reply. Previous owner did the swap. He just bought the engine I believe. Everything else belonged to the car itself.

afnan

Your ECU needs to know when do you engage the AC. It makes adjustments to the RPM. My accord did not had connection when swap was performed. I connected yesterday. Now its fine no significant drop in RPM. Most probably your ECU is odb2b and in that in connector A there are two pins for ECU one for signal one for relay, Have a look at this diagram http://www.ff-squad.com/technet/wiring.obd2b.htm and see for your self.

Note honda uses Ground signal to tell ecu that AC is turned off and ECU Gives ground signal to the relay to turn on AC