Anyone have this problem? I've taken it to mechanic who can find nothing wrong. The AA guy found about 10 faults on the electronic gadget he plugged in but my mechanic says he must've cleared the faults because the car is driving very well now but I'm worried it might happen again. Is this a software issue? Help!!!!

Clearing the stored faults without taking note of what they were doesn't help anyone.

If it happens again make a not of the fault codes

A failing battery can cause all sorts of weird stuff to start happening

Is it mk2.5 ? Did you get any message / warning lights when it slowed down?  On my brothers 2008 focus it would be driving along and engine would just go to tickover speed and not rev with something on the dash saying something like general engine fault, can’t remember exactly what it said. This was all caused to canbus problems in the wiring / connectors.  There are two canbus wires which carry computer type signals between   The ecu, the bcm and the speedo console. Any interruption in the flow of data and the car gets confused and won’t work. 

It might not have had ten current faults. Fault codes don’t have dates on them. Some could be very old from temporary blips which had no relevance to the problem. But they should have been noted down / photo taken of the list.

My son’s 2008 mk2.5 had the engine malfunction and shutting down on to idle recently.  A slap on the dash board above the centre of the instrument cluster temporarily restored power but only for a matter of minute or two .

problem was dry solder joints within the instrument cluster, common problem.

A local refurb company tested, resoldered all of the suspect contacts and gave a lifetime warranty for as long as we own the car.

£96 pounds well spent , so far so good.

testing only would have been £35 if no fault found.

good luck

On 10/14/2021 at 6:58 PM, isetta said:

It might not have had ten current faults. Fault codes don’t have dates on them. Some could be very old from temporary blips which had no relevance to the problem. But they should have been noted down / photo taken of the list.

Unfortunately he didn't get a copy of the faults listed so I guess we'll have to wait for it to happen again 😮 

On 10/14/2021 at 8:03 PM, RL123 said:

My son’s 2008 mk2.5 had the engine malfunction and shutting down on to idle recently.  A slap on the dash board above the centre of the instrument cluster temporarily restored power but only for a matter of minute or two .

problem was dry solder joints within the instrument cluster, common problem.

A local refurb company tested, resoldered all of the suspect contacts and gave a lifetime warranty for as long as we own the car.

£96 pounds well spent , so far so good.

testing only would have been £35 if no fault found.

good luck

Back to normal now after a service but mechanic's not got a clue what could be wrong, he looked at the wiring and couldn't see anything loose or disconnected - he also suggested an auto-electrician which will be the next port of call if it happens again. Thanks...