Need a point in the right direction. My Grandson bought this 98 v6 was told it had an immobiliser problem. Son replaced the ring and main relay. Had someone try ro program and couldnt. I got into the mess and noticed no CEL not green key and no com. through OBD. Did some pin outs on the ECM points me in the direction of the ECM. Is a 37820-P8C-A51 and a 37820-P8A-A02 interchangeable ? Thanks for any help.

 

37820 for Hondas is the PCM. The middle numbers (P8A) are typically not interchangable. The A51 might be interchangable with A50, or A5#. If I recall correctly, the A0# is for manual transmissions, and the A5# are for automatics (or the reverse).

Those PCMS you listed are likely not interchangable. You can try a site like hondapartsnow.com and not put in your vehicle information. Search the part number. Then enter your vehicle information to see if the part is compatible with your car. I'd only use a PCM that is 100% compatible with your car to avoid any massive headaches to get the PCM to work properly.