Mondeo ghia x estate 2002 2.5 v6 tiptronic auto.
Parked my car for an hour the other day and got in it again an hour later only to find engine light on and running lumpy. Checked plugs, leads and changed coil pack for known good one. Very week spark next to nothing on cylinder four. Have wiggled leads and sensor plugs and allsorts. Does anyone know what to look at next? Çode reader fault p0352 Ignition coil B Primary/Secondary circuit came up and fuel sys 1 OL-fault. Thanks in advance.

 

Only time I've seen a coil primary circuit fault was on a Focus 4 cyl zetec, had a short on the loom that runs to the coil pack.

 

I can't see how it could happen just like that but suppose it's possible. Wondering if it's best just to take it to auto electrician as I don't know what to do next!

 

I've found an bumped an old thread that had same fault code.

Turned out to be an ECU fault.

 

I'm going to try and check the wiring from the coil back to the ecu. I'm starting to think it's the ecu myself. If so I need to find out if it can just be swapped with another with the same code or number.

 

As far as i know the immobilser will need coding to the new ECU as the immo (PATS) its built in to the ECU

 

I did wonder.

 

Is it easy to code the ecu to the immo or the immo to the ecu whichever way it has to be? I take it the ecu is removed from car under the dash from inside? Might just send it for repair if it's easier.

 

I'd send it for repair should be plug and play.

BBA reman are good.

 

Any help with the easiest way to remove the ecu from the car would be appreciated very much looks like a hell of a job!

 

Can't for the life of me remember how or where it is lol!

 

I can just about see it behind cubby hole in dash roundabout in front of right knee when sitting in driver seat. Looks like other control units piggy back onto it?

 

Have you even confirmed it is the ecu ?

 

I have checked everything else that I can as far back to past the coil pack. Any other suggestions very welcome.

 

I have checked everything else that I can as far back to past the coil pack. Any other suggestions very welcome.

 

So you're saying "weak spark"....exactly how have you determined this ? With a proper scope/ignition tester, or some sort of spark jumper ? other ?

Have you confirmed the signal to the coils is sound ? Scope current getting pulled for each cylinder pair ?


You could try swapping the leads for 4 and it's firing pair to see if the problem moves to other cylinder, which would be 3 and 4 to see if problem moves to cyl 3

https://talkford.com/community/topic...ht-lead-setup/

Faulty ecu's are usually the least likely cause...perhaps even more so on a wasted spark setup that is firing sparks 2 cylinders at the same time...yet you're saying only 1 cylinder is dead. That doesn't make sense.

 

And as great as the guy is.....I cringe every time I see him take apart live running coils/leads !!!! IMO, don't do that lol

 

Had this on these back in the day and on focus too. Check the 5v power at coil multi plug, if it's showing 12v that shows a problem ecu end.

 

That sounds odd, it looks like an old inductive coil...ie. it should have one 12v, and 3 coil ground triggers from the ecu

5v would suggest it has built in ignitors ? and even then, it would only be the triggers that are 5v based....it still needs a 12v supply.

 

Looking at schematics for it. It appears to be a conventional coil, it should have one 12v feed, and 3 load carrying ground triggers via the ecu.

It would not make sense for there to be 5v anywhere there.

 

I checked the spark with a spark plug tester and also with a spare lead earthing the plug on the block.It was starting to get dark and if I had done it earlier I would not have been able to see the spark at all. I will try swapping the leads on the firing bank and check the voltage into the coil this afternoon and reply later. Thanks so far.

 

I also need to check the current to each pair. Can I do that with just a multimeter with the engine running?

 

No, proper testing needs a scope.

But swap the 2 cylinders leads first.

 

Ok I swapped the 2 leads which are cylinder 1 and 4 on the same bank. I didn't realise that it is actually only running on 4 cylinders. I did check the voltage on all four wires going in and all read roughly 13.4 same as power at battery, unfortunately I don"t have a probe at the mo (have one ordered).

 

A multimeter on voltage for anything other than confirming a 12v supply at one pin on the coil, is useless.

If the multimeter offers pulse width or duty cycle, you could use that to test between 12v and each of the other pins to see if there is a signal at each.

If a pair of cylinders are dead, it could be the coil pack, or it could be the ecu driver for that section of the coil.

A more awkward no tool test, would be establish which of the 3 input pins fires which pair of coils, and switch two about to see if the dead cylinder pair come to life, or if the dead pair stays in the same holes.

ie, which would determine is it an input problem, or a coil/output problem.

 

I wouldn't have thought I could have the same problem on 2 different coil packs though as I already changed it.

 

You just never know.

It's already went from one cylinder down...to two.

test, don't guess.

 

100% my fault for not checking the other cylinder on the same bank. If it is ecu drivers I take it it"s a case of getting ecu off and having it repaired. Do you think repairing it would be the better option than buying a used one with the same numbers?

 

If you get a used ECU it will need the keys learning to it at least, so a job for Ford dealer or mobile locksmith.

If you get your's repaired it shoud be plug and play.

 

So best to get it repaired if thats the case.

 

If it is repairable. You need to balance costs either way between a used ecu, the risk it may be bad, having it coded etc vs getting yours repaired which should be straightforward

If it's a pretty basic ecu, the transistors that handle the current might be something easily replaced. Without opening it up to see though, no idea.

 

Going to do stevieturbo's no tool test tomorrrow. I made up a little wiring set up that I can plug onto coilpack and push the wires from it into the connecting plug to check the input. Cheers for the advice.👍

 

Got spark after stevieturbos notool test. Thanks for the info. Going to remove ecu 2morra and inspect pins for water damage or rust. Then possibly send it for testing. Fingers crossed problems will all be sorted. Thanks all.