Idling issues and "Engine Malfunction Service Now", Fiesta Mk7 S1600

[SwanseaS1600]

Hi, I've been having issues with my Fiesta S1600, coming to a stop it would idle badly with revs rising and dropping, then suddenly drop and stall. Took my car into CEM Days Garngoch for diagnostics and nothing was found. I've lived with this for a while.

The past few weeks I started getting "Engine Malfunction service NOW" errors coupled with the limp home mode which gives little power. The first time they said ignore it as it could be a glitch but it's gotten more frequent, up to 3 times a day. Took it in this week and they found nothing on the diagnostic report.

It happened again after work yesterday so got to the garage in limp mode and as the error was up they got a code indicating the throttle pedal, they swapped mine for one off a demonstrator to let me test the car. (This was the only error their diagnostic tools have ever found and the technician told me the codes get reset after cycling the engine 3 times).

Car was fine last night and this morning, after work the idling problem came back and it stalled a few times, then finally the engine malfunction popped up again.

Ford wanted me to book it in again next week for more diagnostics and to leave it with them for a few days (leaving me without transport) and also charge me £87 an hour for the priviledge. I love the car but can't afford for it to become a money pit. Can anyone offer some suggestions as to what could be wrong please?

Thanks

[iantt]

Probably either the throttle body or crank sensor.

[Tdci-Peter]

1 hour ago, SwanseaS1600 said:

idle badly with revs rising and dropping, then suddenly drop and stall

Hi,

It seems very odd indeed to have that high priority error message with no stored DTCs (error codes). DTCs seem to vary in how long they remain, depending on importance. Some can only be cleared using a scanner.

You really could do with a scanner. A basic OBD2 one, like a U480 type, is Very easy to use, safe, and cheap. Then you can avoid the "3 start problem" while you get it to a garage. This should show all major engine related faults. You need No technical know-how to use it, and once you have a code, Googling it will give lots (too much maybe!) info.

If you have a laptop or similar,  then more comprehensive, Ford specific systems are available, for under £20.

Stalling the engine does not really sound like throttle pedal, the PCM should maintain minimum idle revs at all times. It sounds more likely to be the throttle body, that is the electrically actuated valve that allows air into the engine.

But there are quite a lot of sensors and systems that could do it, so the codes are really essential. (Though they are not 100% accurate, the engine systems have to make assumptions sometimes, and some judgement is needed.)

Peter.

PS: Just seen Ian's reply, came in while I was typing my (longer winded!) one. He usually knows what he is talking about!

 

Edited July 1, 2016 by Tdci-Peter
Add PS

[iantt]

Not allways. Lol

[SwanseaS1600]

Thanks both, I will have to see about getting an ODB2 code reader. 

I'm just a little disappointed with CEM Days as they had the car twice for a day at a time and found nothing and now want to charge me £87 an hour and probably still find nothing, it appears as though, if their software finds nothing, then they don't do very much.

I was wondering if it could be some sort of air flow sensor issue, they say no, however the one time they get a code they say it's the throttle pedal but the problem is still there.

[Tdci-Peter]

19 minutes ago, SwanseaS1600 said:

it appears as though, if their software finds nothing, then they don't do very much.

Very true, but to be honest, they can't do much without it. The cars are just too complex for the old wise mechanics to just have a listen, and say "its the thingummywhatsit" any more That is the price we pay for cars with better power, better fuel economy and loads of (too many?) add on gadgets.

But most sensors, like crank sensor, or air flow sensor, should be giving some sort of code if they are mis-behaving badly. Throttle bodies are a little prone to playing up without being detected by the PCM.

Peter.

 

[SwanseaS1600]

I'm also confused as to whether the 1.6 Zetec has a MAP, MAF or TMAP. I had a Mk4 years ago that started stalling on stopping or low speeds and when I disconnected the air flow meter the problem went away, which isolated the issue.

is the throttle body an expensive part on the Mk7, I just want to get this fixed but don't like the idea of spending £500 just to find the problem, with no guarantee of them actually accomplishing it.

[Tdci-Peter]

6 hours ago, SwanseaS1600 said:

MAP, MAF or TMAP.

A very quick look on eBay (good source of info, & I have rarely had problems with stuff bought).

Turned up a MAP:

http://www.ebay.co.uk/itm/Ford-Fiesta-MK7-2009-2012-Manifold-Absolute-Pressure-MAP-Sensor-2S6A-9F479-CB-/222055622945?fits=Model%3AFiesta&hash=item33b38be921:g:susAAOSwAuNW6WWm

I saw no reference to a MAF for the petrol version. A non-turbo engine does not really need both.

There were lots & lots of 2nd hand throttle valves, perhaps that shows that they often fail!

It is certainly possible that disconnecting the MAP may help identify the problem. The pcm should go into a default mode using a standard value, which could be better or more stable than a defective sensor. Possibly the same with the crankshaft sensor, it can use the camshaft sensor instead. A warning light/message should appear, but the engine should still run, and be more stable than with a defective sensor.

The scanner would be useful here to confirm the message & clear it after reconnecting the sensor.

I could not (quickly) find the price of a new throttle body.

Peter.

 

 

[SwanseaS1600]

Thanks Peter, I'm going to try and get hold of a diagnostics tool myself and see what I can do. I'm not very mechanically minded, so need to try and get to the root course and then get a garage to fix it.

[SwanseaS1600]

Spent £120 on an ODB2 reader. At idle, graphing RPM and mass air flow I can see some drops in the revs and air flow at times, could this be a problem with the MAP sensor? No error codes as yet on the system.

[Tdci-Peter]

20 hours ago, SwanseaS1600 said:

graphing RPM and mass air flow I can see some drops in the revs and air flow at times, could this be a problem with the MAP sensor?

Can you try graphing the MAP?

I am not 100% sure where the Mass flow info comes from. If there is a MAF, it should be in the ducting from air filter to inlet manifold, usually just by the filter. If there is no MAF, then Air flow will be inferred by the PCM from rpm, air temp. & MAP readings. But it may still be a displayable PID (reading).

I still think Throttle valve is favourite. MAP failures are usually quite severe, with out of range readings, that would trigger a MAP DTC. But keep looking, worth trying all avenues before condemning the throttle valve.

Peter.

[SwanseaS1600]

The MAP fluctuated between 0.2 and 0.3, hard to see if it's the cause of the error as I haven't had the engine malfunction since. Wondering if there is a combination, the throttle pedal plus something else. One thing ford mentioned was my VIN is linked to a series which had issues with the injectors and injector rail, causing the potential to stall after starting the car unless some throttle is applied. Apparently Ford didn't consider this a significant enough issue to consider it a recall and if I want to rectify it the dealer will charge £2,500.

[SwanseaS1600]

There is a data cable going to a socket on the ducting from the air filter, presumably this is the MAP/MAF (think the dealer called it a TMAP), the connector didn't want to pull straight off and I didn't want to break anything

[Tdci-Peter]

8 hours ago, SwanseaS1600 said:

The MAP fluctuated between 0.2 and 0.3

Did it say what units that was in? I assume it is Bar absolute, and that those readings were at idle speed. So it would be about 0.7 to 0.8 bar of vacuum, which sounds sensible for an inlet manifold (after the throttle valve).

Does the reading rise when the throttle was pressed to raise the rpm. Also it should read with the engine off, (but ignition on), about 1 bar (normal atmospheric pressure).

TMAP means combined MAP (manifold absolute pressure) and air temperature sensor. But if it is located  by the filter, it can not be sensing manifold pressure, only normal air pressure (less any filter drop). Have a look inside the duct if possible. A MAF usually goes at least half way across the duct, as it measures air velocity near the centre. A TMAP may only protrude a little way into the duct. (I have rechecked a Ford site & eBay for Fiesta MAF sensor, and only diesel versions show.)

I can not really advise on the connector release mechanism, they all seem to differ. Usually there is a slot that a screwdriver can lever in to release a catch, but it is sometimes not at all obvious.

I think you will have to keep testing until the error clearly happens. Throttle valve sticking will cause small MAP variations, but MAP intermittent failure will cause big steps in the MAP reading. It may be difficult to isolate cause & effect. But big steps in MAP reading should generate a MAP DTC.

I would disregard the £2500 stall after start problem for the present. A stall while running should be serious enough to cause a recall (imagine stalling in front of an oncoming artic.. Or perhaps don't!.) But your problem was stall after stop, I believe?

 

[SwanseaS1600]

Hi Peter, I'm not looking at the stalling after starting problem as a rev counters that. I believe that the S1600 has a sigma engine and this forgoes MAF for MAP/TMAP, however trying to find out results in information overload.

One source I found said "the 1.6 Duratech has a MAP instead of a MAF sensor". It goes on to say "issues with the MAP sensor can lead to various problems from excessive fuel consumption, miss fires, erratic idle, reduced engine performance, etc. A malfunctioning MAP sensor will almost always also result in the Engine Check warning light to come on".

The throttle pedal is being replaced Wednesday, since that is the one code the dealer managed to capture, I'll keep monitoring then and possibly remove and clean the MAP.

[Tdci-Peter]

56 minutes ago, SwanseaS1600 said:

A malfunctioning MAP sensor will almost always also result in the Engine Check warning light to come on".

That matches my thoughts, and if the light comes on there should be an associated DTC.

Looking at the Focus wiring diags for the Sigma 1.6 engine, the  DIVVT versions (variable valve timing) versions have a MAF/Temp sensor, the 1.4/1.6 MTX version has a TMAP, & no MAF.

It is a pity we do not have & can't repeat the garage reported code. Throttle pedal errors are usually pretty specific, the pedal has two separate sensing elements, and any significant difference will flag an error.

Hope for the best on Wednesday, pleas keep us posted here.

Peter.

[SwanseaS1600]

This morning on the way to work I had the dreaded "Engine Malfunction service Now" error again but this time had a diagnostics reader with me.  The reader showed the following error: "P2135 Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation".  Considering the dealer supposedly fitted a pedal from one of their demonstrators which was in for work, I'm a little concerned that this popped up, especially as I am booked in to have a new pedal fitted tomorrow.  This is the first time since last Friday that the error has come up (was happening 3 times a day).  Could this be an issue with a connector or with the throttle body sensor instead?

[Tdci-Peter]

5 hours ago, SwanseaS1600 said:

"P2135 Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation

Certainly it could be a connector to the pedal sensor. Or any of the connectors between the pedal sensor and the IC (instrument Cluster) and PCM. It is very unlikely to be the throttle body, based on that code.

The pedal sensor is safety critical, and is dual redundant. So there are two actual sensors. The output of one goes to the PCM, which uses it to control the throttle valve. The other one goes to the IC. The IC & PCM communicate all the time over the HS-CAN bus, and the readings will be compared, and an error flagged (that one) if there is a difference, and the pcm then probably uses the lower (safer) reading.

So as you can see, there is quite a lot of possible error causes in that chain. If it is not the sensor, it could be various connectors, wiring, IC fault, PCM fault, or CAN Bus comms problem.

I do not know whether your OBD system can read all error codes, especially in the IC. It needs a Ford specific system like Forscan to do that.

Carefully note all symptoms & codes, and if & when you reset the codes. I think it is a good idea to reset the codes, so you can then see if they re-occur, but the garage may not agree! And try to make the garage aware that the problem either is not the sensor, or their Demo car sensor is faulty!

For info on Forscan, see:

 

[SwanseaS1600]

Hi Peter,  FORSCAN looks useful, I wonder if there is a Mac version.

I've done the IC self test with the ignition and button on the IC, it doesn't show any errors, all the sweeps go normally, the lights all light up, everything seems normal.

I'm not sure whether the garage would have FORSCAN, but I would assume their diagnostics software would have access to all the same information since they are a Ford dealership and service point, so if there were errors they should have them, but they can't find any.

[Tdci-Peter]

20 minutes ago, SwanseaS1600 said:

FORSCAN looks useful, I wonder if there is a Mac version.

Not that I know. But there is Android & an iPhone App.

(their iPhone download link failed when I tested it, but I did find another route to the App.)

Goto: http://forscan.org

The garage should have the full Ford IDS system, more powerful than Forscan, but whether they know how to use it properly? Who knows!

Just keep our fingers, and a few other bits(?!), crossed.

Peter.

 

[SwanseaS1600]

Hi Peter,  the pedal was changed yestereday, so it's now the "wait and see stage".  They did say that if it hasn't resolved the issue, next would be wiring (and expensive labour), then after that the PCM.  Just have to monitor it now and see what happens.

[Tdci-Peter]

1 hour ago, SwanseaS1600 said:

Just have to monitor it now and see what happens.

If possible, keep a diagnostic system (preferably Forscan or similar) with you. Then you will be able to capture information when it is fresh. Some codes go on repeated drive cycles, other may appear later. For complex, wiring or multi-module faults, All of the information is vital.

I hope it is the pedal sensor or its connector, will keep my fingers crossed for you. Let us know how you get on.

Peter.

 

[SwanseaS1600]

Thanks Peter,  

My diagnostics reader (Clarke Engine Diagnostic/EOBD Fault Code Reader)  is under the drivers seat ready in case!

Kevin

[SwanseaS1600]

Still getting intermittent engine malfunction, same error code as before, happening about once a day when it happens, but not every day.

[Tdci-Peter]

2 hours ago, SwanseaS1600 said:

Still getting intermittent engine malfunction, same error code as before

I guess that is: P2135 Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation

When a get some time, I will try to check the circuit diagram to see if there is some connector(s) that may cause the fault. (Unless anyone else volunteers first, please feel free! )

There seems to be an intermittent disagreement between the readings read by the IC (dashboard) & the pcm.

Peter.