Could use a little more information
What market are you in? USA or Europe or Asia or etc.?
Does your vehicle have an immobilizer? Chip key?
What have you done to investigate the issue?

When it does not start, have you tested for spark at the plugs?
Did you feel the injectors to see if there was any pulse?
Do you hear the fuel pump prime the fuel rail when the key is first turn to the on position?
Have you hooked up a scanner to see if there are any trouble codes??

Edit: BCM? Body Control Module??? Is it messing up the CAN bus system?

 

 

When you try to start and it doesn't, do you see the immobilizer symbol on the instrument cluster?
Usually it is a key symbol to show it isn't reading the key correctly.

No spark, no pulse usually indicates the crankshaft sensor is not working
No signal from crankshaft sensor to ECU ... then ECU will think the engine is not cranking and will not put out spark or pulse.
Sometimes when someone replaces the crank sensor the little rubber o-ring gets stuck
and then the new one will have double o-rings which pushes the sensor out of proper position
Don't believe that is your issue.

Sometimes IAC will stick and cause a no start but you have no pulse and no spark which has nothing to do with IAC
Hmm, seems like something is knocking the signal from the crank sensor out/down
Have seen the down stream O2 sensor wires short which causes similar issues.

Don't know ... just a bunch of guesses.