Been having problems with my Focus 1.6i Zetec. Not starting showing engine malfunction and acceleration reduced when driving.  Changed battery and had new battery in fob key and no difference. Booked into Evans Halshaw last Thursday and was diagnosed with the CAN bus causing the problems. Had fixed and picked car up Friday ok. Not used Saturday. Sunday took it for a drive no problems. Monday out in car no probs. Left it a couple of hours. Went to use it, wont start showing engine malfunction high pitched beeping noise and all lights lit up on the clock. Left it for a bit then started. Phone to re-book in Evans Halshaw but feeling worried as why wasn't the Fault that's re-occurring not picked up. Obviously there is something else wrong. Paying £65 for it to be looked at before anything and they want to charge again to have another look. Any suggestions gladly appreciated.

If it was misdiagnosed its not your fault!!! its the technicians.

 

Get the main earths checked on the battery connections and the main earth for the dash checked by drivers seat area they can corroded causing canbus errors.

 

Thank you for your reply. I'm back there in the morning.

could well be dodgy soldering on the pins on the circuit board in the speedo console. This is well known problem but usually on slightly older cars.

videos on youtube about this, showing how to dismantle. This is not a technically advanced job to dismantle and inspect but is quite fiddly (you have to remove the needles from all of the dials). Inspect solder with magnifying glass and you might see cracks around the pins. Resoldering each pin fixes these is many cases.

There are places you can send it for fixing.

or could be a canbus connector eg. the big plug next to the engine bay fuse box. or the connectors by the front passenger door pillar under plastic panels.

Due to intermittent problems on my brothers 2008 focus I totally rewired the high speed canbus and it has now been ok for a few months. Not an easy job but we were so fed up  with thinking we'd found the fault, cleaning connectors and then it happening again a few days later (I did resolder all of the 32 pins in his speedo console for good measure but I don't think that was the problem on his.

 

Thank you for your comments. Really appreciate them.

Instrument Cluster fault

The large connector on the rear will need resoldered.