2002 Civic EX bought used. Drove car two weeks and realized hack mechanic that worked on car prior to purchase stripped out alternator bracket and fried ECU. This is a California low emission car. Put first ECU box in and would not work. Realized replacement box came from federal emissions car. Researched and found used ECU box with numbers 37820-PLM-L54 pulled out of California car also. The replacement box number matches original box number. Replacement box will not start car. Does anyone have any ideas or come someone help me please!

 

What about the immobilizer?

 

The immobilizer indicator should be illuminated on the dash "green key" when you try and start the car. You must have the key, immobilizer and ECU married by either your local Honda dealership or an advanced service technician with the proper equipment.

 

Ok sorry to sound stupid but where is the immobilize? I do not know much about the computer and electronics on these cars, I can pretty much do anything else.
Thanks

 

It's likely you have a blown fuse, probably the main big alternator fuse going through the engine fuse box, among possibly other fuses.

 

Thanks I will check that

 

The immobilizer is in the computer in the key and in the ignition switch all three must be coded together to work correctly together or the car will never start