Engine Light & Limp Mode

[Luke4efc]

21 minutes ago, M Thomas said:

I appreciate the general advice to get the fault codes read and hope that my friendly local mechanic has a scanner that's up to the job (seeing as some say that fault codes don't always show up).

That's the only advice lol.

You can read them yourself with a copy of Forscan download onto a laptop (free) and a modified Elm327 lead from Tunnelrat (less than £20).

[Tom bush]

Hi guys & girls, 

Ive got a 2013 Ford fiesta 1.0L zetec ecoboost petrol. I was just driving home this afternoon and the eml light came on and the car went into limp mode, the car was fully serviced only a couple months ago and has had uprated spark plugs recently. the engine runs smooth at idle but it did go loud for a short period of time before eml light appeared. this is really annoying as i have an MOT in 2 days and this has never happened before, one thing i can note is that the temperature is dropping being the end of october. 

any ideas on this would be amazing.

Cheers. Tom.

[anon]

The temperature is dropping here as well but my car did not go into limp mode so that will not be it.

The engine went loud and then the EML light went on. 

Have you thought to have a thorough look at the exhaust, from one end to the other?

[anon]

Recently serviced. Who did the work? Has the air cleaner container been dislodged and not correctly refitted? If that were the case and it came adrift, the engine would be loud and the EML would  in all probability light up. Check all the pipes.

[Luke4efc]

56 minutes ago, Tom bush said:

Hi guys & girls, 

Ive got a 2013 Ford fiesta 1.0L zetec ecoboost petrol. I was just driving home this afternoon and the eml light came on and the car went into limp mode, the car was fully serviced only a couple months ago and has had uprated spark plugs recently. the engine runs smooth at idle but it did go loud for a short period of time before eml light appeared. this is really annoying as i have an MOT in 2 days and this has never happened before, one thing i can note is that the temperature is dropping being the end of october. 

any ideas on this would be amazing.

Cheers. Tom.

Without a fault code it's complete guesswork. You need to plug in with an OBD2 scanner (ideally a modified ELM327 cable and Forscan downloaded onto a laptop) and come back here once you have a code.

[anon]

Not necessarily. Sometimes the solution can be found by simply asking the right questions in the right order. There are likelihoods that can be easily verified, in this case, has a break appeared in the exhaust which has been picked up by the sensors that are there in order to do just that. High likelihood.

Just serviced can mean not put back together as well as thought and a disconnected airbox system will almost certainly cause upset. Fair to middling likelihood and both easily checked.

Old school magick, from before we had fault codes.

[Luke4efc]

3 hours ago, anon said:

Not necessarily. Sometimes the solution can be found by simply asking the right questions in the right order. There are likelihoods that can be easily verified, in this case, has a break appeared in the exhaust which has been picked up by the sensors that are there in order to do just that. High likelihood.

By the time you've done all that, you may as well just plug in and it'll tell you what's wrong. Just this week we've had someone on the forum who said he had a transmission fault, to plug in and read the codes and found it was actually something to do with the EGR...

3 hours ago, anon said:

Just serviced can mean not put back together as well as thought and a disconnected airbox system will almost certainly cause upset.

I wouldn't call "a couple months ago" being just serviced. Anything could've gone wrong in the meantime.

[anon]

Luke,  It is quite ok to let the computer do your thinking for you but I prefer to use my understanding first. It is a very much better way of diagnosing problems remotely.

The guy wants to know what to look at, not learn how to use Forscan. Most people don't because most people do not want to. Nor should they have to if the job can be done without recourse to it.

I have given two likely checks that can be done without waiting for a piece of equipment he does not have, spending some time learning how to produce an answer that he will not understand and then having to come back to have it explained to him. I think that will be a much greater assistance to offer practical and achievable advice instead.

[Tdci-Peter]

8 hours ago, Luke4efc said:

Without a fault code it's complete guesswork. You need to plug in with an OBD2 scanner (ideally a modified ELM327 cable and Forscan downloaded onto a laptop) and come back here once you have a code.

Like Luke, I prefer to use the computer to get the codes first, then use whatever understanding of the problem that I have, to see if the codes are sensible, and what they actually mean. DTCs are not 100% accurate, they rely on the ability of the programmer to predict how any particular fault scenario will look like from within the ECU, which is where the programmer has to live, effectively. But DTCs do narrow down the possibilities quite a lot. Modern cars and engines with loads of software, actuators & sensors, are often impossible to diagnose without them.

9 hours ago, Tom bush said:

the engine runs smooth at idle but it did go loud for a short period of time before eml light appeared.

Can you be a bit more detailed about the change in engine sound?

There are at least three causes I can think of. The simplest is an exhaust leak, and this can usually be quite easily verified by listening at various places from the outside of the car with the engine idling. Unless the leak is before the cat, it is unlikely that a smallish leak, that can still make a lot of noise, will be picked up by any sensor on a Ford, so will not put on the EML. Leaks before or in the cat can trigger O2 sensor or lean mix errors, which would show up on most diagnostic systems and light the EML.

The second is a mechanical fault, which could be many things: Low oil pressure, worn crank or conrod bearings, loose timing belt, valve noise due to a faulty tappet, etc. Even just a loose engine cover or rattling connector can make a big change to engine sound. Most of these faults will not generate DTCs or light the EML. Just listening, possibly using a tube as a sort of stethoscope, can be the best diagnosis method.

The third is a combustion problem. GTDI engines like the 1L ecoboost switch between stoichiometric (standard petrol engine) mode and lean burn (more like a diesel) mode. Lean burn mode is particularly prone to increased combustion noise if there are injector or fuel pressure problems. Usually these problems will show up as DTCs.

The 1l Ecoboost is probably the most complex and advanced engine that Ford have ever tried to make. Some faults, like an exhaust leak, can be quickly diagnosed without computer aid, but most problems will require all the help you can get, starting with a really good diagnostic system! If the EML lights, there will be DTCs involved for sure. Some DTCs stick around until cleared, but some disappear very quickly, so prompt code reading using a good reader kept handy can be very useful. By the time a garage reads them, some evidence can have evaporated.

(I used the word "tried" above, because it does seem to me that Ford made some real schoolboy errors in the initial design of the 1l, like over stressed plastic parts, and parts too readily corroded, that result in instant engine destruction when they fail. The whole unit has little margin for error!)

[mserrano]

Hi. My car is a 2015 Focus 1L ecobooster. I am one of those mechanically-challenged guys in all car matters who once again keeps seeing the engine malfunction light appear on the dashboard. I and my local garage are fed up with all the investigations that to date don't seem to have given any clear cause. So I can foresee the garage mechanics groaning if I bring the car again. Let me tell you how it has all developed.

In early August 2021 the EML showed on dashboard and the garage renewed the lambda sensor pre cat and replaced the Lambda Sensor. In mid-September an annual service (75,000 miles) was done by my local garage. To their credit, they have been very good, doing all the investigations at no cost to me, I think they felt responsible as it was so soon after the annual service and MOT (it passed). One month later (mid-October) the EML showed up again. Also twice since then, in early November and mid-November and in each case I had to take it back again. In every case, the garage did everything they could and though in each case they gave me back the car without the EML light showing, the last time I was told by the garage is "keep an eye on it". Well, here we are, a month later, and the EML light has shown up again continuously for the past 3 days. I haven't taken the car back to the garage, but of course am wondering what to do now. Having to call the garage yet again feels a bit like the story of the shepherd crying wolf, but as I am meant to drive up the A1 this coming Friday I am unsure and nervous. What would you do if you were me? 

[Aldridge Andy]

Does your local garage have access to ford diagnostics equipment or are they using something generic?

Why not “bite the bullet” and book the car in to your local Ford dealer who will have the correct diagnostic equipment and plenty of experience in common issues.

I wouldn’t undertake a long journey with the EML light on. You could breakdown incurring recovery costs or in addition you could cause some costly damage. 

[Paige-Angel]

Hiya everyone, I have a 1.6 diesel mk 7 fiesta zetec s. I'm having a few issues with the car but thinking it's all related. The issue comes and goes and is not constant. So we are driving along in the car and the cog light comes on and stays on until the engine is turned off and the car will not rev above 3k, even if the engine is turned off if you turn it back on without leaving it for a few hours or disconnecting the battery the light will go off but the Limited revs stay. We have even tried locking and unlocking the car but the revs stay. If you disconnect the battery or leave it for a few hours it's okay when you come back to it, until the next time it happens. It is now getting progressively worse and more often. The car has now also started lagging when pulling off as though trying to refuse me from pulling away. Any ideas? 

[Luke4efc]

3 hours ago, Paige-Angel said:

Hiya everyone, I have a 1.6 diesel mk 7 fiesta zetec s. I'm having a few issues with the car but thinking it's all related. The issue comes and goes and is not constant. So we are driving along in the car and the cog light comes on and stays on until the engine is turned off and the car will not rev above 3k, even if the engine is turned off if you turn it back on without leaving it for a few hours or disconnecting the battery the light will go off but the Limited revs stay. We have even tried locking and unlocking the car but the revs stay. If you disconnect the battery or leave it for a few hours it's okay when you come back to it, until the next time it happens. It is now getting progressively worse and more often. The car has now also started lagging when pulling off as though trying to refuse me from pulling away. Any ideas? 

You need to read the fault codes. The symptoms you have describe most engine problems...

Once you've done that, I suggest you start your own topic rather than posting on something that will probably have a completely different solution.

[Stiks]

On 1/29/2019 at 9:38 AM, TomsFocus said:

You still haven't answered the fuel filter question...   It's the most common cause of power loss on these which is why I keep asking.  

You're not far from me, I'm happy to put Forscan on it to pull up the codes the generic scanners won't find.  Message me if you'd like to do that.

Hi Tom. My ford fiesta 1.4 TDI went into limp mode after changing the fuel filter. Tried cleaning sensors fuel and air. Took it to a garage and they changed an injector. Changed the egr valve. Still runs the same in limp. I see a few people have mentioned about fuel filter changes, but no-one gives a remedy?

 

 

 

 

[TomsFocus]

1 hour ago, Stiks said:

Hi Tom. My ford fiesta 1.4 TDI went into limp mode after changing the fuel filter. Tried cleaning sensors fuel and air. Took it to a garage and they changed an injector. Changed the egr valve. Still runs the same in limp. I see a few people have mentioned about fuel filter changes, but no-one gives a remedy?

Hi Steve,

What fault code is being triggered?  Seems an odd coincidence for the EGR and an injector to fail immediately after a filter change, sounds like the garage are just throwing parts at it.

If it's a low fuel pressure code then chances are it's something to do with the filter.  Either wrong filter, or not fitted correctly, or damage caused to pipework/fittings during the change.

Also worth checking the round wiring loom plug hasn't been knocked as they get loose over time.

 

[Jezzaj656]

I have the same problem as Alan k470, when driving the service due and spanner appear on the dash. When you turn the engine off it disappears and is not there when you turn the ignition back on so the clutch and throttle press Down will not work, it loses power but a quick ignition on and off resets it. Would not bother me but it’s the wife’s car. Have plugged a sensor in and had two boost faults that I cleared but service light still comes on

any ideas?

[unofix]

4 hours ago, Jezzaj656 said:

I have the same problem as Alan k470

Then the answer will be the same as what Alan k470 was told.

[Jezzaj656]

 

I have the same problem as Alan k470, when driving the service due and spanner appear on the dash. When you turn the engine off it disappears and is not there when you turn the ignition back on so the clutch and throttle press Down will not work, it loses power but a quick ignition on and off resets it. Would not bother me but it’s the wife’s car. Have plugged a sensor in and had two boost faults that I cleared but service light still comes on

any ideas?

 

• Did not see an answer to Alan’s post

[Jezzaj656]

2 minutes ago, Jezzaj656 said:

 

 

I have the same problem as Alan k470, when driving the service due and spanner appear on the dash. When you turn the engine off it disappears and is not there when you turn the ignition back on so the clutch and throttle press Down will not work, it loses power but a quick ignition on and off resets it. Would not bother me but it’s the wife’s car. Have plugged a sensor in and had two boost faults that I cleared but service light still comes on

any ideas?

 

• Did not see an answer to Alan’s post

Thanks for your help unofix , NOT!!!

[unofix]

No problem, always happy to help 👍

You could just for a laugh actually check for the DTC's and then you would get some useful help. 🤔

[unofix]

On 1/7/2021 at 7:15 PM, Luke4efc said:

Perhaps try throwing a dart at this board to find the fault.

In all seriousness you need to read the fault codes and come back.

 

[Macran]

Had a limp mode problem with my Toyota RAV4 recently.Fault code was read by RAC engineer some months ago.Toyota tech was at a loss,until I told him the code that was read by the RA. ——- Try SCV (fuel cutoff valves if they fitted on the fiesta)——