Hi guys my Ford Focus is having problems when setting off it flashes up with engine system fault and all the power goes until I kill engine and restart the car I have had it on diagnostics and it is showing no errors I have had green flag out to it and have had no luck please help!!!

50 minutes ago, Steve green said:

my Ford Focus is having problems when setting off it flashes up with engine system fault

Hi,

My first thought is that it is the Instrument Cluster (IC). Bad connections on this unit are extremely common on Foci of 2005/6. I had it in Feb this year.

When it will not start, is the immobiliser LED flashing oddly? It actually flashes out an error code if there is a problem. And the IC does cause this.

Were the diagnostics done with a generic OBD2 scanner? This does not pick up many of the error codes that can be generated by the IC and associated CAN bus failures.

The bad connections frequently affect the main CAN bus, which is used by all the vital underbonnet modules (PCM, Steering, ABS, and the IC). So there can be a huge range of symptoms. The engine systems light is often caused by CAN bus problems.

If it is the IC, then it can be repaired, usually less then £100. I fixed mine for nothing, apart from £10 for a diagnostic tool, and made a report on it:

http://www.fordownersclub.com/forums/applications/core/interface/file/attachment.php?id=38633

To do the job without massive garage diagnostics bills, you will need an ELM327 interface & the Forscan system, unless you already have an alternative. This will also help confirm the source of the fault.

You will find a lot about ELM327 & Forscan on this site, which together provide a very comprehensive diagnosis & maintenance tool.

For ELM327 see:

http://www.spanglefish.com/TunnelratElectronics/index.asp?pageid=516992

you will also need a program called Forscan, its free and you can get it from

http://forscan.org/download.html

Please post any feedback or further questions here.

Peter