Technical Stalling when using windows

[Jakeblues]

Hi folks, please can someone point me in the right direction, I'm going slowly bonkers !!!
I have a 2008 Fiat Panda Active 1.1, only done 48 k, everything is great......apart from it stalling when using the electric windows and or the heater blower, very rarely it doesn't when idling and even then you can hear the revs drop when operating the Windows, if you push up when the window is already shut it stalls every time. Starts immediately after ok.
I have checked and cleaned battery connections, earth strap at the chassis, ran a battery booster cable as an extra earth to the negative battery terminal, with no affect.
Sometimes it even resets the clock when it stalls, as if power has been interrupted entirely !
I have asked the local garage auto electrician and got 'dunno, never heard of that before' as a helpful reply !! HELP !!!

 

[chris3234]

First. I'd get the battery tested a failing cell could cause issues when drawing a large load
If that's work fine check the main earth cable try bending them if they feel really stiff they probably are corroded internally and could do with replacing

If they turn out fine I'd be looking at the alternator

 

[Jakeblues]

Thanks for that, I've tried the main earth leads and cleaned them up, the battery is measuring 14v with lights and other equipment on with engine running, 13+volts when engine off.
It only stalls when using the Windows or heater fan, I can have the lights, rear
heated window etc. all on and it's fine.

 

[Jakeblues]

Update.....now it's stalling every now and then without touching anything electrical !!! Just when coming to a stop at junctions etc, then starts first time and runs (and idles) fine.

 

[Pugglt Auld Jock]

Our panda is a 2010 1.2 dynamic eco. Whenever there is a particularly heavy demand on the battery the engine speeds up slightly to make the alternator charge harder. I notice it particularly when the windows are being operated especially when the winder motor is temporarily stalled as the window closes fully. I've never attempted to strip down the throttle body but for this speeding up to happen there must be a stepper motor controlled idle speed adjuster in the throttle body. Probably this is either jammed or has an electrical problem. If it can't do this then a stall is quite likely. It's always worth taking the air cleaner off and spraying some choke cleaner down the intake - you may be surprised at how much muck is lurking around the throttle butterfly (I do this every service, keep an old toothbrush for agitation) - also worth unplugging the electrical connectors and having a look for corrosion (verdigris), sometimes just unplugging and plugging back in remakes a dodgy connection. Many years ago I was tempted into buying a tube of Contalube 770. This is a special light grease for protecting electrical connectors - https://www.autoelectricsupplies.co.uk/product/827/category/154 - You just apply enough to effect a seal when the plug/connector is reassembled and it works very well. Whenever we get a new car added to the "Family Fleet" I work my way round all the connectors as I'm servicing it. Rarely get any problems with poor circuits after that. I've still not quite used up that original tube.

 

[Pugglt Auld Jock]

Update.....now it's stalling every now and then without touching anything electrical !!! Just when coming to a stop at junctions etc, then starts first time and runs (and idles) fine.

Looking even more like idle speed control with this symptom. On a closed throttle, as you are slowing down, the fuel feed through the injectors is cut off. Then when you declutch the fuel starts to be sprayed out of the injectors again and, often, the idle speed control needs to open up a bit to recover the engine's idle and stop it stalling. The fact that it starts and idles ok when you turn the key is quite common. I may be wrong - and I often am - but I'd be concentrating on that idle speed control. If you were here I would be connecting up my Multiecuscan and having a look for fault codes because it's quite possible it'll have posted one (or more) which will "point the finger".

Good luck - do please let us know what it turns out to be - and have a laugh at my expense when you prove me wrong!
Jock

 

[DaveMcT]

You can quickly prove the engine to battery earth lead by clipping a jump lead between engine block and battery earth post.

The idle speed is under full electronic control via a stepper motor, The revs rise slightly when electrical load is applied because the system adds a touch more fuel/air when the revs try to dip. If it gets over-eager you'll notice that crawling in traffic can have the engine wanting to run a little faster than you'd ideally like.

Check the stepper motor. Also check the throttle position sensor as that's how the ECU knows the engine is turning.

As a final guess - has the cam belt been changed recently? If it was mis-timed by one tooth that might affect the tickover.

 

[Jakeblues]

Can't thank all of you enough for all your input, I've cleaned the throttle body and butterfly valve thoroughly, no improvement, I will investigate the idle stepper motor connections tomorrow, anyone have a picture of what the connector looks like ?

 

[DaveMcT]

An edit to my comment on Throttle Position Sensor which is part of the throttle valve assembly.

I had meant to say check the CRANK position sensor as that's how the ECU knows the engine is turning.

 

[Jakeblues]

Hi folks update, cleaned throttle body twice, disconnected electrical connections slated with cleaner......no change.
Took to the garage, explained issue, asked if they could increase idle speed, or see if something was affecting it, they 'cleaned throttle body' even though I told them I'd done that, 'found a blocked vacuum hose, tested on a few runs, all sorted'.
Great think I, drive home with window down, park in drive, put window up, car stalls !!! No difference whatsoever !! Grrrrrr.......

 

[DaveMcT]

You need to check the power being pulled by the window motor. The easiest way is to wire in a voltmeter and watch the system voltage while the car is in use. If the window is pulling excessive power or the generator/battery are weak the system voltage will drop.
My wife's car would intermittently show the battery light for 1/2 mile after a cold start. The steering was as heavy as (**). Then as the system warmed, the generator seemed to wake up and the steering came back. BUT she had a good battery so the system voltage never fell enough to stall the engine ECU.

In her case the aux "fan" belt was ok so the fix was a new alternator. I had already checked the power and earth cables with jump leads and nothing was found. By the ways, an alternator swap on a Panda with air con is an absolute bar(expletive deleted).

 

[jasimog]

My 2006 1.2 Dynamic is currently suffering from these mild stalling symptoms. When stopped in traffic the idle speed is very low and any change to anything electrical (e.g. switching the headlights on, winding a window up/down) causes the engine to stall.

The car was fine a few weeks ago, so I'm trying to work through what I've changed recently. Four things I think:

• The crank (RPM) sensor failed before Christmas and I couldn't start the car (fault code logged). I swapped it out for a new one from eBay (Lucas brand) and this allowed me to start the car again. I did check the resistance of the old/new sensors and there was definitely an issue with the old one.
• New Bosch battery fitted, seems to hold its voltage fine, alternator voltage is over 14V when the engine is running.
• Clutch slave cylinder swapped out with a new TRW metal one, much quieter and works fine but of course I did unplug ECU / remove battery tray etc to get access.
• Finally, fitted new spark plugs NGK DCPR7E-N-10, look genuine but bought from eBay.

The issue is permanently present now, but no fault codes are registered.

The thread above mentions to check a stepper motor in the throttle body, which apparently adjusts idle revs based on electrical load. Any more info on this would be appreciated.

What else could I check?

[Edited for clarity]

 

[koalar]

Disable starting, (pull a major relay)
Put a multimeter on low range volts and measure between the block and battery negative (both cleaned)

Crank the engine for a seconds

Should stay below 0.5V

Let's get this out of the way first

Does your car have aircon

I presume your has flyby wire throttle

 

[jasimog]

Thanks...I'll do that test when I can...with an assistant.

The car has aircon, the stalling issue still happens with aircon off.

It's a throttle cable into the throttle body (there is an idle speed adjustment screw on the throttle body, but I haven't touched that yet).

 

[koalar]

Thanks...I'll do that test when I can...with an assistant.

Great

The car has aircon, the stalling issue still happens with aircon off.

Can't be a loose alternator belt as cars with aircon have a spring loaded tentioner

It's a throttle cable into the throttle body (there is an idle speed adjustment screw on the throttle body, but I haven't touched that yet).

Cable throttle surprises me on a dynamic with it's built in trip computer

Thats not an iIdle adjustment screw, that all done via the idle control valve. That screw is set at T/B manufacture and should never need adjusting. Doing so would just add another unknown variable

 

[koalar]

If you have a scantool that reads live data, you can get a pretty good idea of how the alternator coping with different loads by using the battery voltage data stream


The battery acts as a big dampener. The graphs below were taken with a battery that was getting towards it's end of life

Here is the main beam switched on and off
Looks very choppy because of the auto scale, there's a small decrease in revs and voltage. 0.2V drop

And If I leave it to settle there is about 5 RPM drop and 0.1V drop

Here I have all the electrics on, front and rear fogs, fans full, main beam, really struggling to cope revs and voltage are starting to fall 0.8V drop and 50+ RPM drop

 

[The Panda Nut]

First. I'd get the battery tested a failing cell could cause issues when drawing a large load
If that's work fine check the main earth cable try bending them if they feel really stiff they probably are corroded internally and could do with replacing

If they turn out fine I'd be looking at the alternator

I agree with this. 14v when running is a little low too. Its suprising how even a small deficit indicates a failing battery or alternator. Both are things that work one day or fail the next. When the car just stalls, are there any changes / symptoms. We had a few similar issues on our Panda when the battery was going then all of a sudden it went dead. It still showed 12.8 volts when measured but was as dead as a Dodo. Under 80000 miles I would not expect an alternator to be failing in general terms. If it were me I would get an accurate measure of the alternator condition, then ask a battery supplier to test the battery, then do the earth regardless of what it may look like before digging further. Good luck

Its worht saying that in the past car battereis used to get sluggish and indicate impending failure then one day the cars wouldnt go after slow cranking. Both our Panda batteries failed last year. SIgns were subtle, like the window thing, then without warning they were dead. SOmething has changed,,,,

 

[koalar]

The three pandas I have had have been 14.1V as measured with a calibrated meter

Fiat specs are 14V

 

[jrkitching]

then without warning they were dead

I've had several batteries fail this way; some well within their warranty period.

If you want to get a good idea of how worn out your battery is, remove it from the car, and with the battery on the bench, charge it fully, and measure the voltage.

Wait an hour, then measure it again.

Measure it again, twice a day, for a few days.

 

[koalar]

This thread is a resurrection from 4 years ago

I read it as @jasimog has a newish battery