Ford Focus Mk2 - Possible electronic issue?

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Sun 10 Jul 2016 18:36
Ford Focus Mk2 - Possible electronic issue? - gumbidave

Hi,

Looking for some help with a couple of issues my 59-plate Focus has developed.

I bought the car 13 months ago and everything has been fine... until recently. When turning the ignition on, the yellow engine warning and ABS/TC lights come on and remain on until about 15/20 seconds after I start the engine. As well as this, I can't operate the electric windows until the warning lights go out.

Once the car is moving, everything is fine - no warning lights and no issue with the windows. But the next time I start the car, the issues return. There are seemingly no other electrical issues - no other warning lights or inoperable electrics. Does anyone know what could be causing this?

Also, the car is trying to stall itself when in neutral. When slowing to a stop (traffic lights, etc.), I go down through the gears until about 10/15mph when I take it out of gear. As I bring the car to a stop the revs keep dropping and the engine begins to stutter - if I don't push the clutch in, the engine stalls. What could be causing this? How could it be fixed?

Thanks in advance for any help.
If any more info is needed, please don't hesitate to ask and I'll do my best to answer.

:-)

Reply | Report as offensive | Link
Sun 10 Jul 2016 19:04
Ford Focus Mk2 - Possible electronic issue? - FP

Someone more expert than me will be along shortly, but I do know that there was a software update to the management system of petrol engines of this vintage a while back. Among other issues it addressed was hot starting.

You don't say what engine you have.

Reply | Report as offensive | Link
Sun 10 Jul 2016 19:14
Ford Focus Mk2 - Possible electronic issue? - gumbidave

Oh nuts.
I knew I forgot something.


Engine is a 1.8 petrol.

Reply | Report as offensive | Link
Sun 10 Jul 2016 19:29
Ford Focus Mk2 - Possible electronic issue? - elekie&a/c doctor

Before doing anything major,I would get the battery tested.It may start the car ok,but if the voltage under cranking drops too low,then this could cause electrical gremlins.

Reply | Report as offensive | Link
Sun 10 Jul 2016 20:41
Ford Focus Mk2 - Possible electronic issue? - 3uga

Yep, battery test is fine for a start. This type of care gets mad when not suplied with the corect voltage/amp

Reply | Report as offensive | Link
Sat 16 Jul 2016 13:33
Ford Focus Mk2 - Possible electronic issue? - gumbidave

Apologies for the delay in updating - it's been a busy week.

I have now had the Battery, Alternator and Starter Motor checked and they all appear to be working normally - no voltage drops, no charging/discharging issues, nothing.

However, I do seem to be suffering from worse mpg than usual - have dropped from 34-odd to 33-ish... Not a massive drop I know, but could that be related? Or do I just need to learn not to be so heavy with the right foot?

Regards,
David.

Reply | Report as offensive | Link
Sat 16 Jul 2016 16:09
Ford Focus Mk2 - Possible electronic issue? - hardway

How to explain this......

Well everything in that car that has a chip is called a module,

engine,door windows, C/locking,ABS...... on and on.

Even the dam radio!

And the vehicle runs a scan on start up for comunication,

Called coms for short,

And module not functioning correctly can cause problems.

For example I've seen a non cranking car with a new battery/starter and alternator and a very upset owner.

His problem was actually a bad connection in a multi plug in the passesngers footwell!

The point I'm getting at here is these are remarkably electrically complex vehicles.

Even the alternator charging is governed by the engine ECU!

Sometimes it doesn't even comand the b***** to charge the battery!

Anyway given all this the first thing I do on these is run a global scan for comms between every module and code read for any faults on ANY module.

Even the dash/speedo module has a chip,

And the big fuse box/relay plate up under the dash in the passengers footwell.

Which by the way is also known for faults.

You just would not believe the factory wiring diagram for these!

So "Global scan" for comms and fault codes.

And see if there's any evidence.

Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide