Engine Malfunction

[Rozzaxw1]

Hey all, 

Im looking for any suggestions of what might be causing this weeks headache. 

Cars been chugging along fine with no issues then today whilst doing 70 on the motorway the dash lit up like a christmas tree with the warning of Engine Malfunction. The engine didnt actually appear to lose power and after pulling onto the hard shoulder and turning it off and on it seemed all fine again.

Then in the evening  after picking the kids up it refused to start all together. The key turns as normal but the engine doesnt even try to start.. Engine Malfunction...

I managed ti get it going again by locking the doors and unlocking them a few times, so this would seem like immobiliser issues. But that wouldnt explain the motorway problem..

Anyone got any ideas?

Ps. 1.6 petrol focus 2008

Thanks

[Tdci-Peter]

On 19/12/2016 at 7:12 PM, Rozzaxw1 said:

I managed ti get it going again by locking the doors and unlocking them a few times, so this would seem like immobiliser issues. But that wouldnt explain the motorway problem..

If failure to start was due to the immobiliser (aka PATS), the PATS led would flash rapidly for a minute or so, then alter to flash out a code. Typical flash code:  1 flash -PAUSE - 6 flashes = flash code 16 . This would indicate a communications (bus) problem between the PCM (aka ECU) and the instrument cluster (IC).

A bus problem also will typically light lots of lights on the dash. While driving, it may not have much effect.

2006 Foci were prone to this problem due to faulty ICs. Yours is out of this range, and may be wiring connector problems. There are a couple of big connectors just in front of the passenger door, behind the trim panel there. These can give problems. Also there is a big connector in the engine bay fuse box.

There is a simple test that can be done on the HS-CAN bus, which connects the IC to the PCM.

Stick a couple of suitable probes (un-bent paper clips can work quite well) in the diagnostic connector pins 6-14, put a DMM across the pair on voltage range, turn ignition on, note reading, turn ignition off, wait till voltage drops to zero (+/- 1 or 2 mV), switch to resistance range to check for 60 ohms.

It should be stable at close to 60 ohms, any deviations would indicate a problem.