Hi all i have a 2012 MK3 focus with the 1.6 ecoboost 180hp. Recently it didn't start after doing about 100 miles. And after checking all wiring, grounds, fuses, starter and everything else in between I found it had 3.4v on one side and 2v on the other of the starter relay control pins when ignition is on. I checked this on many other car all different makes and unless the key/button is in start position i should have 12v at all other times i should have 0v. After a few more tests and code scans I decided the PCM is internally damaged (the only codes I have are for circuit high on alot of sensors) I sent the pcm away for diagnostic and repair with ACTRONIC in Chelmsford and they said all is well with the PCM. I havent seen anything like this in all my years as a technician. Has anyone got any advice before I either scrap it or take the car to ford. Cheers,  Patrick 

Welcome!
My very simplistic answers are to use Forscan to check for codes (I  KNOW you say you've read "codes") and relevant live data before you take it anywhere (if that hasn't been done)
Otherwise if the starter relay won't operate, will a direct (fused) wire direct from battery get it to operate?

4 hours ago, Patrickmk3 said:

Has anyone got any advice before I either scrap it or take the car to ford.

Get a good auto-electrician to take a look at it.

Check fuse F30 in the engine fusebox.

Hi chaps. I have checked every single fuse on the car and that it has power same with relays. Im reluctant to get someone to look at it as I'm a technician with over 5 years of experience and a colleague with 20 years of experience have both spent about 12 hours looking at all the wiring as such on the vehicle and can't find anything odd. Spoke to a ford tech that I used to work with and he suspects that a cam or crank position sensor has internally failed and is back feeding voltage into the module 

As said, is there any live data related to those sensors or the correlation OR as you're a tech either get access to a scope or buy a cheap one to investigate the sensor outputs OR I don't like just changing components without testing but that is your choice OR get someone else to look at it if all of that fails to avoid scrapping?

There are multiple videos (Picoscope, Diagnose Dan, Intelligent Auto, Milligan Auto Services) on You Tube that, to me, have good in depth diagnostic processes.

And assume you haven't tried my last suggestion of wiring to solenoid to get it cranking or not?

Yeah I tried bridging the relay and it turns over and sounds fine. It just wont start even with foot on clutch and ignition on when you turn it over. Won't bump start. I spoke to an old colleague of mine that was a tech at ford and he said check crank pos sensor as they can fail and send voltage back into the module but wont give a fault for it.