Hi all - Got a 2014 500c 1.2 and when run from cold has no EML NOR Stop/start issue lights on dash. Car can idle for a good 20 mins and warms up nicely, but when you drive let’s say maybe 10 mins, the stop/ start amber warnings come up saying stop start unavailable, but car still runs fine until you come to a stop and idle again, then the eml lights up with a check engine warning and then drops into limp home mode. Can switch off and restart the car and can drive it normally but still have the eml and stop/start ambers in the dash. ODB reader has P0101 code. If you leave the car for a while ( few hours) and you restart it the cycle starts again.
Have replaced the MAP sensor for a new Bosch one, cleaned the throttle body, and replaced the battery with a new stopstart one . Alternator ok too.
Have had a look for any obvious air leaks and can’t see anything obvious in or on the intake manifold
I understand that if the car detects any issues it will shut off the stop start stuff first, but can’t seem to clear the eml permanently. I think if I can get that sorted it’s likely the stop start will sort itself out.
anyone have any other ideas?
Hello Hennoir,
FYI if it may help. Follows is an experience to share (I searched the Forums for insight along the way, as recommended to you. I'm posting simply to add to the knowledge base, not as a solution for you per se).
2014 500 1.2 FIRE 32k
After a couple of trouble free years, my problem started out with (unfathomable) intermittent S/S unavailable, then became engine warning light, yellow triangle, sometimes followed by limp. Then light(s) would go out seemingly of its/their own accord. Then back on. Then progressed to turning into limp-mode. Then come out of limp mode of its own accord.
This was all Greek to me - the last time I looked under a car bonnet, the only electronics were sets of points and a coil.
Took it to local mechanic, fault reported was MAP sensor, replaced. Problem recurred, fault reported was air leak at inlet manifold, rebuilt with new gaskets and cleaned throttle body etc. Problem recurred, fault reported P0101 (I don't know what codes were previously reported and whether or not included P0101) and inlet manifold leak (again).
When I say 'problem recurred' - sometimes the light would come on then go off again, sometimes followed by limp mode which would then go away. What I didn't know at the time was both can go away on their own e.g. switch off engine and goes away after a while, leave overnight and EML may go away. What a frustrating PITA (not knowing that that is 'how it works'). Dumbass system IMHO but what do I know? So I'd limp home for 20mins when I could have sat with engine off for 10 mins then resumed. EML would come on, but drive ok. Go to supermarket, come out and light disappeared. Talk about flailing about in the dark when it comes to trying to diagnose what the heck is going in. I went to a hospital appointment, 40m drive all good. Came out after an hour, started up and lights on and in limp (40m from home). Switched of 10mins, no limp, lights on. Drove home no problem. Next day no warning lights on. Clearly Fiat and I have a very different understanding of what meets the definition of a fit-for-purpose diagnostics system.
Anyhoo, back to mechanic. Had already done battery check, past. However, on retest found that whilst it past check on battery, it failed as soon as the car was started i.e. it tested good 'static', but as soon as cold crank to start battery then showed as fail. Replaced battery.
Problem recurred, inlet leak. Performed smoke test - no leak identified.
A little 'detail', 2 different mechanics looked at it. The second (who replaced battery and did smoke test) said MAP sensors have been known to fail, and aftermarket non-oem cheap China knock-offs have been known to play up with ECUs but he'd checked and replacement was NGK known-brand so not obvious candidate.
After much more of my time spent (AFAIK I only get one life, & whilst I believe some think to the contrary I'm going to go with that) I decided replacing MAP sensor at least was within my capabilities & with no leak on smoke test, manifold rebuilt etc etc suggesting the ECU may be telling porkies (or, more accurately, the whole error code diagnostics can be close to pretty effing useless), investigated the MAP sensor. Found replacement Bosch part on FleaBay was less than a Bobby so went ahead.
I haven't had a problem since, covering approx. 1k. Fingers are still in crossed mode.
The MAP sensor replacement was not NGK, it was NTK, whoever they may be. When I took it out, it was covered in oil. As I understand it (only from reading around, otherwise I know diddly), it shouldn't be, because it measures air. So, in terms of 'logical process of deduction/elimination', would suggest MAP shouldn't be oily hence replacing it may not have been a problem with it nor 'cos not Bosch, and replacing may mean new one is not reporting problems because it is not oily - yet.
Next suspect (so far as I can deduce) could be PCV valve stuck or leaking o-ring. However there are no other indications other than oil on MAP i.e. no oil visible anywhere around inside engine bay.
Then there's the petrol tank evap thingy rabbit whole to reside in but there's never been anything reported to suggest that direction be pursued.
However, the laughingly titled 'diagnostic' system of error codes has said there's a problem with air leaks when a smoke test says there isn't, etc etc.
Along the way I purchased an OBD and confirmed the error repeatedly as P0101 (MAF or MAP, seems to depend on who you're speaking to) and changing the MAP (for a Bosch OEM one (relevant ?)) definitely seems to have fixed it - for now.
I haven't even been able to find where the PCV valve is on 1.2 FIRE (YT vids seems to show on 1.4/Arbarth), I believe it may be some pipes at the back of the inlet manifold, so if I get P0101 and find it is oily again it will be going to the mechanic again. For now it has not yet been allowed down off the naughty-step. Maybe after another 1k trouble-free.
So, pick the bones out of that lot. Can't say anything definitive concluded.
FWIW what I 'think' may have happened is two, perhaps more, problems conflated.
Firstly, I think the s/s unavailable may have been the initial and separate issue. Because it was unfathomable and intermittent, and the battery tested good, the mechanic just reset the error code and it was 'good'. Until it wasn't. The battery DID subsequently fail on test, but effectively only after starting the car. That sounds to me like a battery failing i.e. shows voltage but failing capacity to store amps. Coincidentally my neighbour had had a very similar problem with her Landy Evoque - similar age, 8yrs. So not unexpected at that age. Dumbass diagnostics is smart enough to disable s/s but not to tell you why.
Secondly, it may or may not have had inlet leak (causing error messages and limp) - I say that because it has reported it, the manifold has be rebuilt, but still reported it when smoke test says no. So who knows.
Thirdly, MAP sensor replacement of unknown brand with Bosch has led to current reliable motoring. Removed sensor was oily. As I understand it it should not have been, so may not have been a faulty sensor.
No conclusions per se.
What a right royal PITA. Reason I decided to post is not a solution, rather that most every post I read on your topic is a similar runaround of erratic and inconclusive tail-chasing
Perhaps it helps to know you're not alone
Best,
