I have installed new pcm and reprogrammed the old one to the new one. But now when I try starting the car the green key flashes and only cranks. I have also already checked the ACG fuse and it’s fine.

2012 Honda Accord 2.4l EX-L

 

Scan all modules.

 

Green flashing key is the immobilizer telling you that the key transponder is not sending the correct signal for the immobilizer to give the PCM the okay. This stops the gas pump from working and the injectors from working as well. So, when you say you reprogrammed the PCM, ???? Did you program the PCM to the engine and to the immobilizer and then the keys to the immobilizer? This requires a high level scan tool capable of doing this. Maybe there is a Youtube.com video showing this process???