Non Starting P38

Non Starting P38
Hi i wonder if anyone can give me some advice, i have a petrol p38 4.6 with the Bosch injection, the problem is that it wont start. It has fault codes:
P1666 Engine anti-theft signal circuit malfunction BCU serial link frame/ bit timing error
P1667 Engine anti-theft signal circuit low Serial link short circuit to earth
P1668 Engine anti-theft signal circuit high Serial link open circuit.
The garage has checked connection but code P1666 will not clear any ideas would be gratefully recieved

Thanks Bob

Seems to be some conflicting codes there...

How can a circuit be both Open Circuit and Short Circuit at the same time, or are the High/Low circuits seperate...??

What reader did they use?? some readers don't decode properly as the P38 OBDII socket doesn't use a true OBDII protocol....

I have a suspicion it is the much fabled BeCM to Engine ECU sync problem....

The BeCM needs to handshake with the Engine ECU before it will allow the car to start....oftentimes they lose the sync code and needs to be kicked into line again using a BBS Syncmate, or a diagnostic computer...

Do a search on here (not the google search) it may give more clues

Hi Saint V8 the sync code has been reset and is still showing, The only code that will not disapear is the P1666 code. The engine turns over fine, I parked the car connected it to an optimate charger as battery kept going flat and has not run since.

Petrol or Diesel and which year??

If the sync is out, one certain models, the engine will turn over but not fire....!!!

1999 with the thor engine petrol 4.6