Ford Focus II - Occasional faulty link between PATS and EEC module

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Fri 22 Mar 2013 13:38
Ford Focus II - Occasional faulty link between PATS and EEC module - jerrican

I'm looking for some help in tracking down a weird immobiliser issue on my Focus Mk2 1.6 tdci late-2005.

First attempt to start in the morning always fails - immobiliser led flashes for about 1min then gives code 1:6 "Faulty link between PATS and EEC-V module". Remove key, wait 5 mins, then car starts first time and is (so far) OK for the rest of the day.

Same issue with both keys. No DTC fault codes.

I think the immo code means no comms between key and engine management unit. If I change the ignition lock (but reuse the barrel), will this also change the PATS transponder? If not, where is the transponder located? I wiould like to check for dry joints in connectors, so are there any other PATS modules between the ignition lock and engine management unit, and if so where are they?

Thanks in advance.

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Fri 22 Mar 2013 17:32
Ford Focus II - Occasional faulty link between PATS and EEC module - elekie&a/c doctor

I would check the fuses and contacts in the engine bay fuse box for cleanliness and tightness.One of these does these immobiliser system(can't remember which).The pats/immobiliser system is part of the instrument pod.If you do decide to pull this out,be extremely carefull ,as the front of the pod can crack very easily.The key reader around the ignition barrel is part of the immobiliser system ,but not a coded part.You could check the connector to this.Replacing the ignition lock is a waste of time.The transponder is in the key.hth

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Sun 24 Mar 2013 12:27
Ford Focus II - Occasional faulty link between PATS and EEC module - jerrican
elekie - Thanks for the very helpful reply - I appreciate it. I'll take a good look round at fuses and wiring joints when (?) the snow clears, and post back here.
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Fri 19 Apr 2013 14:30
Ford Focus II - Occasional faulty link between PATS and EEC module - jerrican

This PATS problem appears to be in remission. After the snow cleared, I first checked over the engine bay fuse box, as elekie suggested, but found nothing amiss - reseating fuses, etc made no difference. Likewise with the fusebox in the cabin. I then found that (not too hard) " 'ecky thump" on the dashboard above the instrument cluster was sufficient to remind PATS of its duty, so decided to check further in the cabin. The PATS transceiver around the ignition lock has a 4-pin electrical connector with very thin pins (more for a computer than for a vehicle) which would be susceptible to damp and corrosion. After reassembly, the problem seems to have gone away.

This reminded me that I had a similar result with a dead speedo on a Peugeot 406 (1998) - reseating electrical connectors on the instrument cluster invariably brought it back to life. Perhaps different component manufacturers use slightly differrent alloys in plugs & sockets, setting up for corrsosion and high contact resistance after 5 years or so of damp winters. Then as now, simply reseating connectors has saved a bundle on replacement panels.

I tried and failed to remove the instrument cluster on the Focus (something I can't see is holding it at top centre) so it may have a dry joint restored temporarily by disturbance. Does anyone know what the trick is to removing the instrument cluster on a Focus II (late 2005)?

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Fri 19 Apr 2013 19:17
Ford Focus II - Occasional faulty link between PATS and EEC module - elekie&a/c doctor

The trick to removing the insrument pod is to not crack the perspex front.At the top centre is a spring clip that needs to be compressed to release the pod.hth

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Sat 20 Apr 2013 17:57
Ford Focus II - Occasional faulty link between PATS and EEC module - jerrican

The trick to removing the insrument pod is to not crack the perspex front.At the top centre is a spring clip that needs to be compressed to release the pod.hth

I've managed so far to avoid cracking the perspex but I can't see the spring clip. I've tried sliding a flat knife blade in towards top centre from either side and from the front, but cant release it. Is the spring clip at the front near the perspex or set further back?

btw elekie, I appreciate your help - thanks.

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Sun 21 Apr 2013 11:30
Ford Focus II - Occasional faulty link between PATS and EEC module - elekie&a/c doctor

It is more like plastic ribbing on the cluster that locates into the hood of the dash aperture.You need a wide,thin plastic trim tool to allow the pod to ride out .In the centre section,slightly to the back of pod.hth

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Sun 28 Apr 2013 18:17
Ford Focus II - Occasional faulty link between PATS and EEC module - jerrican
Tried again to remove the cluster but no luck. As the problem went away, after I re-plugged the key transceiver or because of the better weather, I've decided that it ain't broke so I won't fix it any more until next winter.

elekie, many thanks for all your help - much appreciated.
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Fri 20 Dec 2013 15:58
Ford Focus II - Occasional faulty link between PATS and EEC module - jerrican

Found the solution - hope this update might be useful to others.

Problem recurred during the warm summer months. At 70mph on the M40, all lights come up on instrument cluster and engine goes into idle mode. 'ecky thump' on the dashboard above the instrument cluster provided an instant solution and got safely to destination (in slow lane!) with only a couple more recurrences. Time this was sorted once and for all.

Removed the instrument cluster. Easier said than done, cos the dashboard seems to have shrunk a bit over the years and the serrated strip on top of the cluster had bitten deep into the dashboard foam. Took the cluster to a specialist electronics repairer in Waterlooville, Hants (unsure of publicity rules on this forum, otherwise I would name them) who confirmed the fault and replaced "a couple of components on the motherboard". They were coy about further details but - as an former electronics engineer - I'd guess these were two power capacitors. I knew as soon as I walked in through the door I knew I'd come to the right place - instrument clusters piled high and deep - and they'd known what the issue was as soon as I phoned them. Cost about 20% of what I believe a dealer would have charged to replace the cluster.

The problem has never recurred and engine starts first time, even in the present cold damp winter weather, so I'm confiident this is the solution.

Unlikely though it seems, long distance fuel consumption has also improved in the 6 months since the repair by 5-10%. And the temperature gauge appears to show a slightly lower running temperature (say 85degC down from 87-88degC). If I'm right about the power capacitors, then it may be that the instrument/EEC power line voltage was off spec, and if this affects the EEC sensors causing the engine to run even a bit hotter, then I am wondering if this could exacerbate hot running that leads to injector seal breakdown and suibsequent turbo failure (which I had a few years ago). All very speculative, but could the cause of 1.6 tdci turbo troubles on well serviced verhicles be down to two low cost components in the instrument cluster??

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Fri 20 Dec 2013 17:05
Ford Focus II - Occasional faulty link between PATS and EEC module - elekie&a/c doctor
nice fix to the pod.However this has no effect or control on the engine management system other than the immobiliser circuit.in fact once the engine is started,the pod can be removed,and the engine will run fine.
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Sat 21 Dec 2013 18:25
Ford Focus II - Occasional faulty link between PATS and EEC module - jerrican

So much for fine theories!

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Fri 9 Aug 2019 10:47
Ford Focus II - Occasional faulty link between PATS and EEC module - Patryk_tt

The problem is not low quality components/capacitors, nothing needs to be replaced. It's the lead free solder what causes all issues, not only in this car but in entire electronics industry. In automotive, End of Life Vehicles Directive is guilty for that.

As elekie&a/c doctor explained, instrument cluster has no influence on engine systems once you start the engine. You think that the engine runs cooler after instrument cluster repair because the person who repaired it did not put the ECT needle into correct position, that's all.

https://totaltronics.com

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Thu 26 Jan 2023 20:51
Ford Focus II - Occasional faulty link between PATS and EEC module - Jay Carruthers
Thanks for taking the time to update your thread with the Fix. I’m wondering whether the fault I’m facing could be similar. I had what I thought was a dead battery after coming out of a shop. I tried at first to get a friend to jumpstart me when this didn’t work. I thought it may have been. I had crappy jump leads, so I borrowed a battery pack from a friend who lived local. I tried this to no avail where I had broken down, was at the top of a hill, so thought I’d try a bump start. We managed to get the car up to a decent speed but try as I might. The car wouldn’t start my partner called out the RAC who first of all tried charging the battery. I was not there at first, but got a call saying could I bring down the other key as he believed the immobiliser wasn’t recognising the key when I arrived the gentleman said the fault was probably caused by starting the car before the immobiliser had disengaged I did point out to the gentleman. How could you start the car before the immobiliser had disengaged? Surely the purpose of an immobiliser is to stop a car starting I’m not doubting that Mechanic had far superior knowledge than I, but I also know when someone just wants to go home LOL. We had to then fired again for a recovery which took 42 hours and two parking tickets before the car was brought back to our home. Thanks to forums like this, I have discovered I too am getting the same fault number one, followed by six rapid lights so the RAC advice of calling out a mobile locksmith, would have just been a waste of several hundred pounds. I’ve checked all of the internal fuses in the foot well and will follow your sage advice on checking those in the engine compartment on another Ford owners forum. I’ve read that it possibly could be a faulty battery which can give the same fault code. If anyone knows the best place to start looking for the cause of the fault I’d be much appreciated.
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Fri 27 Jan 2023 09:21
Ford Focus II - Occasional faulty link between PATS and EEC module - Topdude

Difficult to read the above post as it is one big block of text !

I suggest you follow the advice above and remove the instrument cluster and either re-solder the connector pins or send it away for repair as this is a well known fault on a Mk2 Focus.

My Focus is not giving a problem yet but i am considering doing the re-soldering as a preventative measure.

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