rangie wont start

My rangie P38 2.5 DSE won't start was doagnosed BeCM fault. I've had my BeCM reprogramed fitted new under bonnet fuse box still wont start just turns over untill battery goes flat. Plenty of fuel pumps ok must be electrical any ideas.

It may be the Becm and Engine ECU EMS codes do not match. If they don’t match it will crank all day long.

Check the 12 pin white plug in the driver’s side kick panel. By your right foot.
Check for any of the pins going green and causing bad connection. This plug has immobiliser signal wire. If Becm sends immo signal and doesn’t get a reply because of bad connection it will not start.