Hello,

Wondered if I could get some help with an issue that has befallen my car lately.

So, it first happened about a month ago, but when I start the car, it starts no issue, but then the engine starts to struggle and splutter to a point where it gets to nearly stalling but never does.

I turned the car over a few times and it eventually sorted itself out....

Until a couple of days ago when it started again as I was heading out...

Managed to get it back home and called the AA to take a look at it.

In typical fashion, the car behaved itself and they couldn't find any issues with it but they did pull off a few codes from the computer:

P2191

P0171

P2193

P0174

and suggested I get it looked at by a garage who should be able to investigate further....

Well...I took it in this morning as its due its MOT and asked them to take a look and they are also none the wiser about what's happening. So, I wanted to ask here if there is anyone out there who has an idea of what could need looking at.

I've also got a couple of videos that I will share to hopefully explain what I'm talking about a bit better:

https://streamable.com/px9yal - From the inside, this was me revving a bit while stationary, you'll see that the rev counter goes right hte way down and I am trying to rev there as well, but nothing is happening.

https://streamable.com/duainc - From the engine, you can hopefully hear the spluttering I'm talking about.

It's currently still in the garage now so if you have any ideas, I can give them a call and tell them what to check.

Thanks in advance.

All of those codes suggest the air/fuel mixture is too lean.

First thing to check would be for any damaged vacuum pipes around the intake. 

I just spoke to the garage and they think they might have figured out the issue.

Apparently, because I changed the battery in the car, it needed to be reset.

They did that and they said that it's currently working as expected, but they want to keep it overnight so that they can run from dead cold to make sure that has really solved it.

I honestly didn't even know that the car would need a reset after a battery change, so didn't even think of it being a possible issue. And Halfords sure didn't tell me that when I had them change it.

I'll have to look into how to go about resetting the battery myself if I ever find myself changing the battery again...

1 hour ago, RoryJC said:

Apparently, because I changed the battery in the car, it needed to be reset.

are they saying the BMS needed reset on a 2011 Focus ? 🤔

I think I smell some BS.

Mk3's do have a BMS for variable rate charging.

I'm not convinced this fault has anything to do with the battery though.

Honestly, I have no idea.

It seems a bit odd that a new battery would cause that sort of issue, but who knows...

I'm waiting for further feedback from the garage because they're not going to service it until they figure out that problem first.

(Passed the MOT though, so that's something right? Small wins and all that..)

When I replaced my battery the BMS did not need reset and the car worked exactly the same I just had to re-setup some radio channels.

2 hours ago, F0CUE said:

When I replaced my battery the BMS did not need reset and the car worked exactly the same

I understood (but perhaps wrongly) that BMS was not introduced on to the Focus until late 2012 or early 2013. This may be wrong as @TomsFocus has suggested. However in any event, resetting or not resetting the BMS (if fitted) would have no effect on how the engine was running. Also within 24 to 48 hours the BMS will have established the condition and SOC of the new battery without the need to do anything.

It is of course the correct thing when fitting a new battery to reset the BMS so that the system will reset the battery age counter to zero days, and delete any learnt charging characteristics of the old battery.

I don't know if this helps any....

But I noticed this was happening when I was using non-premium petrol in the car.

After the first time it happened, I used premium petrol almost exclusively for that period and then my partner filled the car with the non-premium stuff.

Not sure if that has any bearing on what the issue could be...

But before the first time I encountered this, we were using the non-premium stuff all the time and it was fine.

4 minutes ago, RoryJC said:

But I noticed this was happening when I was using non-premium petrol in the car.

After the first time it happened, I used premium petrol almost exclusively for that period and then my partner filled the car with the non-premium stuff.

Not sure if that has any bearing on what the issue could be...

But before the first time I encountered this, we were using the non-premium stuff all the time and it was fine.

That makes more sense. Just as a trial put a couple of gallon of the Super Unleaded 'E5' in and see if the running improves.

Out of curiosity, if it does improve after putting the premium stuff in, what would the issue be?

A bad batch of petrol?
General degradation as a result of using not very good petrol for a prolonged period?

Just want to get an idea so I can avoid it happening in the future.

16 minutes ago, RoryJC said:

what would the issue be?

Set of new spark plugs would be my starting place.

1 hour ago, unofix said:

Set of new spark plugs would be my starting place.

Ok, I'll mention to the garage tomorrow when I speak to them to make sure that they fit a new set.

I'll report back with whatever they say.

Thanks

Good morning.

Just got off the phone to the garage and mentioned to them about spark plugs.

Apparently, they sorted the issue by resetting the ECU in the car. Not the BMS.

I asked them to change the spark plugs anyway as a precaution as as far as I am aware, they haven't been changed since I've owned the car and I'm nearly at 100k which is when they suggest they should be changed anyway.

15 hours ago, unofix said:

I understood (but perhaps wrongly) that BMS was not introduced on to the Focus until late 2012 or early 2013. This may be wrong as @TomsFocus has suggested.

I had a Jan 2012 1.6 TDCI with a BMS so can definitely confirm that.  The 8v 1.6 TDCI was available from launch (2011) with stop start, so they must all have a BMS?  The 1.0 EcoBoost was then introduced early 2012 with stop start, so again must have a BMS.  As far as I'm aware, both cars used variable charging alongside the SS as a means to get into the cheapest tax bands.  (Not just SmartCharge like the Mk2's.)

The OP's car is a 1.6 Ti-VCT, so no stop start, and brought over from the old Mk2 (and expensive tax).  In theory, it wouldn't need variable charging or a BMS, so it did cause me some doubt when posting yesterday.  Hopefully they can confirm whether there's a BMS on their negative cable when they get the car back from the garage. 

1 minute ago, TomsFocus said:

so no stop start, and brought over from the old Mk2

but as we know some Mk2.5's did have Stop/Start and no BMS 😉

Just read an old thread of yours last night 👍 It does seem however that the OP's car does have BMS although he now says that the garage has reset the ECU and not the BMS.

1 hour ago, TomsFocus said:

Hopefully they can confirm whether there's a BMS on their negative cable when they get the car back from the garage. 

What exactly would I look for to know it has the BMS?

1 hour ago, unofix said:

but as we know some Mk2.5's did have Stop/Start and no BMS 😉

Which Mk2.5s had stop start?  16v 1.6 TDCI 110ps was already in the £30 tax bracket from 2008 without the need for SS.  (I'd never had moved to Ford if it wasn't! 😮 )

Only one that may have needed it is the ECOnetic trim designed for fleet users.  Do we know for sure that that particular trim didn't use a BMS though?

 

*Edit - Catcar does appear to show a BMS specifically for the 99ps Econetic model on Mk2.5.  

Europe, Focus CB4 2008-2011, 4 Electrical, 41401 Electrical.Battery Cables & Horn, 4140110 Battery Cables And Horn - Catcar.info

17 minutes ago, RoryJC said:

What exactly would I look for to know it has the BMS?

Just an extra lump on the negative battery cable terminal like this.

Out of curiosity, ask to take the old plugs with you, and examine them for any small carbon traces on the ceramic, if there are, this would highly point the fault to them.

4 hours ago, StephenFord said:

Out of curiosity, ask to take the old plugs with you, and examine them for any small carbon traces on the ceramic, if there are, this would highly point the fault to them.

Too late. Got the car back a couple of hours ago.

So far it seems to run alright, but a few other non-related issues were flagged up that need looking into.

Haven't had much chance to check it all over as I had to dash out again for work.

But I'll look for that BMS thing tomorrow when I'm back home.

On 12/6/2023 at 12:53 PM, TomsFocus said:

Just an extra lump on the negative battery cable terminal like this.

Ok, I had a look for it and it looks like it may have one.

The negative is awkward to get at without pulling out the entire battery which requires moving some other bits in front of the housing.

Also, a bit of extra info that I wanted to add.

The guy at the garage reckons that there ECU's keep alive setting was out of whack hence the reset.

I took the car out for a drive today and it seemed fine enough.