Immobiliser Peugeot 406 1998

[Lion406]

In short, lost the last original key. I have a new key without a transponder chip using the key code. The company came by to program a new key with a new chip (reading the computer (ECU)), but it didn't work. Couldn't get into the computer. Then bought a similar ECU with the corresponding transponder chip. The engine started 3 times, that was it. The immobilizer is in between again, can’t get the engine running again. Sent the original computer to remove the immobiliser (immo off), but it doesn't seem to work either, due to not getting into diagnosing, I can't get into the 2nd computer either. 2nd computer, is waiting to have the immobiliser removed. If that doesn't work, maybe an injection sensor? Can an ECU from a 406 only be read with pp2000? The 2nd ECU also didn't want to be read with general reading equipment. The car is not worth towing to the garage and spending a lot of money on it, does anyone have any tips, suggestions or ways to get the immo off. Or is there someone who can do this well with this type of car/computer? Or am I missing something perhaps? I have also tried the antenna ring around the key cilinder. Fuel pump works properly. Anyone have any ideas? Is it infra red maybe? Or a relais, or something else..? Please..

[wheeler]

was it running ok before the key was lost?
This should have been a simple job if you had the correct key chip type & the 4 digit immo code for programming.
When you use another ECU & transponder chip you also need the corresponding CPH unit from the same car as the ECU, CPH & transponder chip are all matched together.