Mitsubishi Repair Problems? Ask a Mechanic for Answers ASAP
Hello, I hope you are well, my name is ***** ***** I will see if I can help you today.
The 2002 Diamante uses a chipped key / transponder style immobiliser system and the new or replacement ecu would need to be coded into the immobiliser using diagnostic programming equipment, without the coding being done, the system would effectively be immobilised.
You need to have the new or replacement ecu coded into the system for the immobiliser system to function and the ecu to allow engine starting.
This would need good diagnostic equipment and not a cheap obd code reader.
I hope this helps you answer your question as to why it will not start, if so please rate five stars as this is the only way I get credit for my time and research, please feel free to ask any follow up questions you have, I aim to be as helpful as I can, from a remote location! ;)