Hi everyone. I’m wondering if anyone has encountered similar, or has words of advice.

I have a 2017 Smax 2.0 diesel. Twice in the past couple of months, the engine management warning light has come on and the car has gone into its limp home mode. If I stop the car, turn it off and then back on again, the light has gone out and the car drives fine. Bizarrely, both times it has happened, I have been driving from Telford back to Newcastle. The first time it happened was around Wetherby. The second time was around Leeming. Weird coincidence that it was in similar parts of the journey?

My usual garage has said it is nothing to worry about unless the light comes on and stays on. If the light has gone off, will the fault code be stored so that someone with a reader could see what has triggered it in the first place?

Cheers

T

I think that your car going into limp mode in a potentially dangerous situation is something to be very worried about if I’m honest.

will the fault code be stored so that someone with a reader could see what has triggered it in the first place?

it should be but not for ever. If your usual guy isnt interested the usual chains (Halfords, Kwikfit etc) usually do a fixed price code read as a service. Interpreting what the codes mean (not looking up the code but knowing what it might really indicate) wont result from that but if theres a something that fits the pattern of the driving when you’re seeing the light (stead motorway driving rather B roads or town driving – not the car having a general dislike of the Yorkshire stretch of the A1M) that might be useful

Cars usually have a range or responses when you’re getting the EML on from it just being on to various degrees of limp. Losing power like that seems to suggest the the management system thinks the cause is important enough to do that.

I’ve never heard of your vehicle but used to have endless EML light issues with an old VW. On for a bit, off for a bit… you start to see patterns everywhere and it consumes you. Buy a cheap code reader off ebay  which should at least point you in the right direction. Or you could do what i did and have the garage remove the bulb. Up until recently though the maximum I’d ever spent on a car was £400 so… YMMV

Oh yeah, limp mode. Used to carry an adjustable spanner in the glove box, disconnect negative for half an hour… job jobbed.

Try a new garage. My van did this a couple of times till took it to garage to sort out. Going into limp mode on the motorway is not much fun and lorries are big and scary when putting on the anchors behind you in a desperate attempt not to crush you.

Or you could do what i did and have the garage remove the bulb.

You paid for that? Haven’t you heard of gaffer tape?

IME, Engine management lights that are intermittent are often a sensor failure rather than something just about to explode.

IANAM though I’d get it checked.

The EML will come on when it detects a fault condition then put it into limp mode to protect the engine. But if it runs for some time without detecting the condition again, then it will start again and be okay until it happens again. Is it something to worry about? Yes. It might get worse, and it’s certainly not convenient. And yes, the code will be stored, sounds like your usual garage can’t be bothered to help – so go somewhere else.

In a turbo diesel it’s highly likely to be something to do with the air management part. If the ECU asks for a certain amount of boost and it doesn’t think it’s getting it, it will go into limp mode because it knows something is wrong and doesn’t want to destroy the engine. This could be:

– an air leak in the pipes or intake manifold
– sticky turbo vanes, meaning it cannot control the boost properly
– a faulty sensor that’s incorrectly reporting the pressure.

I had a problem on mine with the boost pressure sensor wiring. When you start the car it compares the reading from the boost sensor to a reference air pressure sensor – before you turn it over they should match. If they don’t, it goes to limp mode. When this happened to me I would stop and wait for 5 mins or unplug and re-plug the sensor – that seemed to fix it for a year or so.

Oh yeah, limp mode. Used to carry an adjustable spanner in the glove box, disconnect negative for half an hour… job jobbed.

That’d work for some issues, not for others.

You paid for that? Haven’t you heard of gaffer tape?

😊

I seem to remember thinking EML light on being an MOT fail so wanted to thwart them. No idea if true though. But it was reassuring not having to think of the bloody EML light. Until it went in to limp mode whilst flying down the fast lane.

I’ve never heard of your vehicle but used to have endless EML light issues with an old VW.

You can get stickers for your VW

Mines been on for about 3 years now

Halfrauds wanted £90 to pull the codes last time i asked.
I joined the AA, then got them to pull the codes, mine was crank position sensor going wobbly.
You need Ford Bluefin iirc, then you will find a number, like p90002. A trawl of Google will tell you the bad news.
My 2p worth, coked vanes on the hot side of the turbo, need some W O T and lift off to idle to get them moving properly.
They are like one of those random adjustable caulinder tjingsvyour gran had and get sooted up.
Dont leave it like your crap garage recommends, ax it fail when its most inconvenient, ie Xmas morning or on the way to airport and wont re boot with a off then on again swervy

Mines been on for about 3 years now

🤣

I have a new (to me) VW now, but I’m wise to their ways and carry a £6 eBay code reader. When the light occasionally pops on I just pull over, clear the code and I’m on my way.

You need to find out why it’s coming on and what the issue is. Presume the car has got an OBD port so get a cheap OBD2 code reader and pull the codes – Google will tell you what the codes relate to and hopefully an idea of why the EML has been triggered – you can decide if it’s something you need to worry about/fix/ignore.

I’d get it sorted. I ignored mine for a fair while but when it came on on the M6 and basically switched the car off I decided to do something about it 😅
It was a crankshaft position sensor (on a Hyundai i20)

Just had the Fiesta’s light come on. Although it’s stuck on, and I’ve lost the code reader.

I seem to remember thinking EML light on being an MOT fail so wanted to thwart them. No idea if true though. But it was reassuring not having to think of the bloody EML light. Until it went in to limp mode whilst flying down the fast lane.

From the MOT testing book of doom:

8.2.1.2. Gaseous emissions

Engine malfunction indicator lamp (engine management light or ‘EML’)
Turn on the ignition and check that the engine malfunction indicator lamp (MIL) illuminates and then goes off. On some vehicles it will be necessary to start the engine before the MIL goes off.

You need to inspect MIL fitted to:

petrol vehicles including hybrids with 4 or more wheels, not more than 8 passenger seats in addition to the driver’s seat and first used on or after 1 July 2003

So nope, just removing it isn’t an option.

If you were really inventive you could wire it up to the alternator light or something. But TBH that’s probably more effort than actually fixing it given how much of an effort to remove some dashboards can be.

Mines been on for about 3 years now

Depends what it is. Sometimes important, sometimes not.

Friend’s Toyota Landcruiser got warning light but each time the mechanics managed to temporary got it sorted (switched off), then one day the light won’t turn off (warning light on all the time) and his engine was completely gone. Needed new engine but the cost was too high and no mechanics around the area were able to deal with 2T 4×4. Sold the car off as spare for someone else for £500.

Yes, check the warning light because in the worst case scenario your engine is slowly dying. If the mechanics can only switch it off but not find the fault then it is a matter of time you engine died.

So nope, just removing it isn’t an option.

Huh, it sailed through seven more years of MOT’s at random testing stations after i removed the bulb. Until it failed on pretty much everything else in one go and went to the great scrapyard in the sky.

Many years ago I had a Renault Laguna with the tyre pressure sensors. They would regularly (every few trips) show a problem when I was passing Newbridge just outside Edinburgh on the M9. Nowhere else. If I stopped to reset them they’d be fine. I came to the conclusion that it was some sort of radio interference related to passing the end of the runway of Edinburgh Airport.

Is RAF Leeming still operational?

Get someone local to do a diagnostic on it and download the codes, prices can vary quite a bit, best bet is to either use word of mouth to find a decent mechanic/garage who has the kit, or use something like a facebook local group to see who’s best for service/price.

2017 Ford diesel, EML puts you in limp home mode, my moneys on the EGR Valve, bloody useless things.

I have a Bluetooth odb2 reader (cost about a tenner) and the free Torque lite app on my phone as we do get the odd fault light on our old car… always the same fault but worth checking

If it’s going into limp mode I’d want it checked. Depending on what it is the codes might point to the exact problem, or narrow it down to a multitude of things. Either way, you’re probably right to be paranoid: something is going bad and it’s not likely to get better.

 the worst case scenario your engine is slowly dying

No the worse case its it suddenly and spectacularly dying. Seeing someones diesel engine running away in the middle of rush hour motorway traffic – trying to get their children to safety through lanes of traffic in thick clouds of smoke … the guy wasnt having a good day.

They would regularly (every few trips) show a problem when I was passing Newbridge just outside Edinburgh on the M9. Nowhere else.

I used to have an old MGB. Which surprisingly didn’t have and EML.  Driving down an almost deserted M74 on Christmas Day I heard a toot of someones horn – gave ne a bit of a fright as I didnt think anyone was around. There wasn’t. Toot. ………… ….Toot…… Toooooooooooooooooooooot. My horn was suddenly just blasting out – couldn’t be stopped. It had an old style centre horn push and I pulled it out and snapped the wire and it keeps blaring.

Pulled over on the hard shoulder next to the sign to Ecclefechan – popped the bonnet located the blaring horn and pulled the wires out. Fine – peace restored- continued on my way.

Later replace the horn sounder -it was pretty corroded and something had obvs gone awry.

Next year – decided to travel down on Christmas Day again and take advantage of the quiet roads – and ended up on the same bit of hard shoulder again pulling the wires out of… the other horn sounder which has spontaneously started blasting out on the same stretch of road. Turns out it the car had two of them 🙂

The next year left the MG at home and drove down in my van on Christmas Day instead – passed the same spot and had a little chortle to myself about the horn incidents but nothing of that nature this time. 20 minutes later the van ejected its whole exhaust system, from the manifold backwards and I had to make the rest of the journey with ear defender on. 🙂

That made me proper lol 🤣

Anyone explain what’s going on with the car in the youtube video? The oirish lads made a grand crack of trying to explain so they did but i couldn’t make head nor tail of it.

^ turbo seal gone – it’s a diesel aka compression engine so it’s running on crankcase oil that’s leaking past the turbo into the inlet side of the engine. You can turn the ignition off / take the key out and it’ll keep running.
Only way to stop is 5th gear and stall it, cover the air inlet or do the world a favour and let a Mk1 Freelander kill itself.

Interesting. Thanks.

https://forscan.org/home.html

This is great for Fords. Programmed my s-max for a towbar with it for the cost of the dongle.

I had a dodgy engine management light as well, turned out to be too much pooling around Yorkshire trying not to make the kids sick. A decent run on the motorway in 5th (out of 6) cured it.

Dodgy starting was a fuel filter, if it hasn’t had one the oring goes bad and let’s air into the fuel.

My old Skoda used to go into limp mode, I got used to de-clutching, turning it off, turning it back on, then easing the clutch back in, all without bothering to stop, barely even noticing any loss of speed. I believe it was basically just the turbo dying. Never had a service, oil change or any of that stuff, just topped up oil and water, do whatever was necessary to get it through an MOT each year, then gave it away after fifteen years of ownership. It was nineteen years old at that point.
Never showed an EML.

I think that your car going into limp mode in a potentially dangerous situation is something to be very worried about if I’m honest.

I can’t think of many situations other than a really stupid overtake (which was already dangerous to begin with) where a sudden onslaught of limp would be overly concerning, it does coast down rather than coming to a crashing stop. Timing belts and crank sensors on the other hand…

Anyway, sounds like my Civic with the sticky vanes and my C8 with the sticky EGR. A code reader should give you half a clue of where to look but leaving it is not recommended. You can either go for something Forscan compatible or a U480. I have the latter and it’s been fine for the few occasions I’ve needed it on my Mondeo and C8.

I can’t think of many situations other than a really stupid overtake (which was already dangerous to begin with) where a sudden onslaught of limp would be overly concerning, it does coast down rather than coming to a crashing stop

Depends on the car. I’ve had both the Merc and the Passat in limp mode. The Merc still has reasonable power and can drive at 70mph on the flat easily. The Passat would slow down quite dramatically and was only good for 40mph so would be a major issue in a busy but moving motorway.

Huh, it sailed through seven more years of MOT’s at random testing stations after i removed the bulb. Until it failed on pretty much everything else in one go and went to the great scrapyard in the sky.

your car probably predated 2003 (petrol) or 2008 ( Diesel) when that rule came into effect

But i do think its quite impressive how many people are quite open about driving around in a broken car.

But i do think its quite impressive how many people are quite open about driving around in a broken car.

That all depends on what you refer to as ‘broken’. In my case I plug the reader in and it tells me that the exhaust oxygen sensor is playing up (AGAIN!). So I just reset it, then drive until it comes on again (normally 3 – 4 weeks). Repeat until you get bored of resetting it and then just leave it on.

When it goes for its MOT, the garage just reset it (AGAIN!) and it stays off for the required amount of time required for it to pass. Job jobbed.

Its a VW 1.8 T petrol engine BTW. If you talk to pretty much anyone who has owned one, I’m sure they’ll report similar stories. Its just what they do.

Our Mk3 Honda CRV orange warning oil light comes on after a few miles. I checked the oil levels religiously and came to the conclusion that it’s a sensor fail. It’s been like it for a couple of years now. The red STOP! oil pressure warning light has not come on so I gave up worrying.

buy a code reader. itll save you a fortune!

binners
That all depends on what you refer to as ‘broken’. In my case I plug the reader in and it tells me that the exhaust oxygen sensor is playing up (AGAIN!). So I just reset it, then drive until it comes on again (normally 3 – 4 weeks). Repeat until you get bored of resetting it and then just leave it on.

When it goes for its MOT, the garage just reset it (AGAIN!) and it stays off for the required amount of time required for it to pass. Job jobbed.

Its a VW 1.8 T petrol engine BTW. If you talk to pretty much anyone who has owned one, I’m sure they’ll report similar stories. Its just what they do.

Have you actually replaced the sensor though? It’s a £70-100 part. Even when the EML is not on, it will most likely be making the engine run too lean. Then when the light is on, the engine will most likely run a bit rich as a safe default.

That all depends on what you refer to as ‘broken’. In my case I plug the reader in and it tells me that the exhaust oxygen sensor is playing up (AGAIN!). So I just reset it, then drive until it comes on again (normally 3 – 4 weeks). Repeat until you get bored of resetting it and then just leave it on.

Surely it’s easy to replace?

Anything on the exhaust has the potential to be an utter corroded/welded together mess.

Had threaded exhaust sensors that are so stuck that the shell of the exhaust starts to buckle before it comes loose.
Have seen a couple of manufacturers who actually have spanner flats on the bosses to help with removal…

Well, another garage has looked at it, just did a quick diagnostic and it came up as the EGR valve sticking – Argee called it right. They have reset it and suggested that I let the engine warm up properly (min 20 minutes) and then cane it through the gears a few times. Hopefully, that will clear out any of the soot that they think is causing it to stick. If it doesn’t, said that it might be possible to remove it and physically clean it, but if that doesn’t work, reckon on £300ish for a replacement. I’m hoping thrashing it does the trick.

@ Scotroutes – I think RAF Leeming is still operational, but not sure in what capacity. The Hawks that were used for aggressor training were based there, but I read a while back that all of the Hawk T1s were going to be retired (other than the Red Arrows), so I’m not sure what happened with those. I think it still gets used for visiting air forces during exercises; there were some Swiss FA18s there recently.

EGRs *tend* to stick due to a mix of soot and condensation. So a sticky mess.
So you might not be able to blast it all out through the gears, but they are generally fairly easy to remove (even DIY) and only need a bit of a scrub.
Last one i did was a mixture of brake cleaner, WD40 and a tooth brush. Funnily enough, a ford 2l diesel. And before that a VW 1.9 PD engine, and then another VW 1.9 PD engine… None of them needed any more than a good clean, and all took <2 hours. Hopefully yours is equally as easy to reach!