I may need to replace the ECM on my 2001 Civic DX. Car hard starts, runs OK for awhile then goes into limp mode. Have checked values on all sensors (good), checked fuel pressure, checked for a possible head gasket leak and no vacum leaks. Throttle body works fine. Computer throws no codes unless I actually disconnect a sensor.
So i'm getting down to thinking either a bad ECM or relay. My question is I see "plug and Play" ecms on line. Does this mean I just swap ECMs and the car will start- or do I need to get some kind of programming done for the ignition to work?

Is there anyway to determine the ECM is bad using a scan tool?

Thanks for any and all answers in advance.

 

Probably not a bad ECM but can't be ruled out without a swap.

You will need to program the immobilizer for the swapped ECM.

 

Do you know of any videos or links on how to program the immobolizer?

 

Any other suugestions on what I could look into next?