Technical Euro6 1.2 Throttle Response, Hill Start Issues & Watchdog report

[TrevC]

HVF, when you say the revs rise as the clutch is raised, does this allow you to pull away without touching the accelerator? My 500X does this, raising the clutch pedal increases the revs to 1000rpm, the car pulls away, and you then feed in throttle. A bit strange, but I've got used to it, and find it quite handy for low speed maneouvering. The ECU keeps the engine at 1000rpm whenever the clutch is engaged. It can be a bit disconcerting when you lift off the throttle and the car doesn't slow down until you dip the clutch though.
Does it have the problem of pulling away up hill though?

 

[HVF Fiat500]

Hi TrevC,

Yes, that's it! Raise the clutch and the revs increase to around 1000rpm. As you say, great for slow speed manoeuvring and parking. It's my daughters car and she says it isn't very smooth pulling away, it seems to pause just after launch as the ECU changes the throttle control from clutch switch to throttle potentiometer. It is exasperated on a hill start as, just after pulling away, there is a little lurch (caused by the higher throttle setting I suppose).

I was going to experiment with removing the switch and seeing if that helps, I realise we'll loose the SS but i might be worth a try.

Could anyone please advise where the pesky little thing is?

Many thanks,
Mike

 

[TrevC]

I would suggest she perseveres and gets used to it, as I have on my 500X. If you start messing with the clutch pedal sensors, you could be opening a whole can of worms.
I've a feeling that when I read about this on the 500X forum, one of the more knowledgable contributors stated that the clutch pedal sensor was a proportional position indicator, like a potentiometer, rather than a switch. I've had a look but I can't find the post again.

 

[HVF Fiat500]

Thanks TrevC, I think you are right about it being a potentiometer rather than a switch. As I recall, the revs increase proportionately as the clutch pedal is slowly raised, it doesn't suddenly jump to circa 1000rpm.

The car will be visiting this w/e so I'll double check.

 

[jrkitching]

If you disconnect the wiring to the sensor, then you'll get an error message.

Sone have just removed the sensor & wiring complete and taped it out of the way.

 

[Andyb80]

Having had a fair bit of experience with this issue, thought I'd just share what I know. So there is the anti-stall feature that increases the idle to allow you to pull away without touching the throttle. This doesn't effect normal driving in anyway. Then there was the actual lack of power issue which was a severe lack of power under 2k revs, and made it near impossible to pull away or accelerate up a steep hill. The software update to fix this worked on our car.
However there is another issue (as mentioned) where when pulling away with for example 1.5k revs, as you get to the biting point the revs with increase to about 2.5k revs, then when you continue to raise the clutch the revs with drop back down making the car lurch slightly. You can prevent the lurch by playing around with the throttle or bringing the clutch up slightly more abruptly.
Anyway, I have driven about 4 other 500s (64-66 reg) and they all do the same, so I presume it is just a carictoristic of the car and not part of the hill start problem.

 

[TrevC]

I've not noticed any problems pulling away smoothly with the 500X, but that has much more torque so perhaps that's why.

 

[bilo999]

Having had a fair bit of experience with this issue, thought I'd just share what I know. So there is the anti-stall feature that increases the idle to allow you to pull away without touching the throttle. This doesn't effect normal driving in anyway. Then there was the actual lack of power issue which was a severe lack of power under 2k revs, and made it near impossible to pull away or accelerate up a steep hill. The software update to fix this worked on our car.
However there is another issue (as mentioned) where when pulling away with for example 1.5k revs, as you get to the biting point the revs with increase to about 2.5k revs, then when you continue to raise the clutch the revs with drop back down making the car lurch slightly. You can prevent the lurch by playing around with the throttle or bringing the clutch up slightly more abruptly.
Anyway, I have driven about 4 other 500s (64-66 reg) and they all do the same, so I presume it is just a carictoristic of the car and not part of the hill start problem.

I've sort of learnt to drive around this problem and minimise it, but its not gone and I do find myself a bit cautious pulling our of junctions....


Can people confirm what software re-map and clutch position switch / sensor you have asked the fiat dealer to apply as I'd like this done if possible. Drove a new latest 1.2 500 - completely different from our 1.2S 2013 model.

 

[John202020]

Not a Euro 6, but I noticed a strange thing on our 59 plate, if I increase the revs whilst stationary, it goes from idle to 1000 then jumps to 2000, a slight release of the throttle it suddenly drops back to 1000 there's nothing in between, I've tried many time and its always the same bar one occasion when I managed to get it to 1500, but then, it stayed at 1500 with my foot off the pedal only a blip on the pedal and it went back to normal, does not seem to effect the cars normal driving, and has no clutch pedal switch.

 

[Andyb80]

I've sort of learnt to drive around this problem and minimise it, but its not gone and I do find myself a bit cautious pulling our of junctions....


Can people confirm what software re-map and clutch position switch / sensor you have asked the fiat dealer to apply as I'd like this done if possible. Drove a new latest 1.2 500 - completely different from our 1.2S 2013 model.

Sorry I was only told my car had a software update, so I don't know anything about a re-map/clutch switch. The current model 500 1.2 I drove was exactly the same as my 2014 car, so it's interesting that the one you drove was so different.
Also I did try unplugging the clutch switch a while ago. It stopped the increase to 1k revs when bringing up the clutch, but didn't stop the 2.5k rev increase.

 

[SAXA]

Hi, I have the same issue with my 2012 S&S 1.2 lounge 51k.
The S&S doesn't work but no warning lights or pending faults.
Seem to have a slight misfire / judder when taking it steady but revs fine when pushed. Feels like an old diesel when pulling away with a bucket of pedal before any response. Will try a new coil pack just in case, I have fitted quality spark plugs and given it a full service. Fees like a vacuum issue but isn't. Get the feeling it will turn out to be a programming issue with the way the revs change as pulling away. It has caused me to stall and lurch of the line. End up racing off to get over the lag and sudden rush of revs then the dip. No good for fuel economy either. Maybe releasing the software so others can check it out would work?
Very interested in others findings.

 

[p6baseunit]

I had my local fiat specialist at the time remap the ECU on our 1.2 63plate and its like a completely different car! Like unstrapping an elephant from the back!

 

[bob1969]

Euro6 1.2 Throttle Response, Hill Start Issues & Watchdog report

I have the same issue on our 17 plate 1.2 lounge bring the clutch up revs raise and you move apply throttle bogs. If you add throttle and bring the clutch up it trys to add a 1000 revs at the top of the bitting point. Otherwise it goes well and pull in 5 at 30 on flat ground. Only 7k on the clock so dont try that too often. I will ask the dealer to look at it on the first service.

 

[bob1969]

Resolved by doing Murphys panda mod. So much better now without the clutch switch.

 

[renus]

Hi I have a 16 plate 1.2 lounge stop/start with the same problem.When I removed the clutch switch leaving it connected the car drove brilliant no rev increase or flat spot but the engine light and yellow triangle came on with warning of no stop/start.I have since reconnected the switch to the pedal and aventualy all returned to normal obviously complete with rising revs and flat spot.Does yours have stop/start and if so how did you get found this as reading back Murphy's panda didn't.

 

[bob1969]

Hi I have a 16 plate 1.2 lounge stop/start with the same problem.When I removed the clutch switch leaving it connected the car drove brilliant no rev increase or flat spot but the engine light and yellow triangle came on with warning of no stop/start.I have since reconnected the switch to the pedal and aventualy all returned to normal obviously complete with rising revs and flat spot.Does yours have stop/start and if so how did you get found this as reading back Murphy's panda didn't.

You lose stop start if you move the switch still connected. I have since reconnected the switch to the clutch pedal and done a clutch switch relearn via multiecuscan. Its still got the flat spot but as long as you pull off at 1500 rpm and ignore the 500 rpm rise its ok. I put back on as my partner preferred it.

Since ours is 2nd hand I have dosed it with Redex which improved it a bit. I noticed that it cleaned a lot of soot out, so wonder if the plugs are getting fouled as the heat range is wrong hence causing the flat spot

 

[renus]

Hi thanks for your reply .Since reconnecting the switch to the pedal the wife has filled up twice with shell flower and says there is a noticeable improvement .Ours was also second hand with 3000 miles and is still under warranty till march 2019. Fiat have had it back once but we were just given the usual that it is a carcteristic of the car and we need to adapt to it.Funny none of our other fiats over the last 20 years were like this. I shall have another go at them when it goes back next week for a new door handle and aerial under warranty .

 

[renus]

Sorry shell flower should have read shell V power.

 

[bob1969]

Euro6 1.2 Throttle Response, Hill Start Issues & Watchdog report

Yes there is an improve. I used to dose our Panda with Redex every now and again and found a lot of soot covering the back of the car like the 500. I notice the exhaust has now turn from black to a whitish colour. As you said the flat spot is still there but not as noticeable. Its due its first service soon so will have ask the dealer to look at it.

 

[bob1969]

Euro6 1.2 Throttle Response, Hill Start Issues & Watchdog report

Found the problem oil covered MAP sensor. Flat spot gone under 2k. Car hasnt used oil so must of been before the the rings bed in. Much better now with no hole in the rev range now