Hi, I have recently bought a fiat punto 54 plate 1.2l. I have been driving around and one day the engine management light came on. Took it to the garage and they said it was the coils so had them changed, light came back on, the computer said it was still the coils so the garage replaced these again as well as a lambda sensor. Light has come back on again and not being very technical I really am not sure what is wrong.

Reading the forums it sounds like it could be the ECU but the car is driving fine, no longer shuddering or anything since the changes.

Am i causing damage to drive the car like this. also when the light is on petrol consumption is very high. Is there a way I can reset the light when it comes on.

PS not technical at all so sorry as I can tell this is much covered ground.

Hi and WELCOME TO THE FORUM! :wave:

Do you know which fault codes the garage are getting?

There is no way to reset the light unless you have a code reader OR if you fix the problem, the light will turn itself off.

If your fuel consumption is shooting up when the light is on, then i would advise you not to drive the car, as its likely that its overfueling. This can be bad for your engine/ cat converter.

How long after the garage fixed it the first time did the light come back on?

Also, what spark plugs are you using?

Alan

If the lambda is faulty the engine will start ok but run rough when hot and use excessive fuel. The rich air/fuel mixture makes the plugs sooty so they missfire.

The throttle body can also affect the mixture if it needs cleaning.

So - get the Lambda sensor tested and clean the throttle body using proper carb cleaner and cotton buds. You will need to take it off the car to do the job.

If it is still acting up after that lot it might be the ECU. I read recently that one fault is where you can swap the coils over but it missfires on the same two cylinders (if the coil was faulty the other two would missfire).

There are firms which can repair these ECUs. Dont get stuffed over for a new one or yet another set of coils.

Hi thank you for your very quick replies.

Alan,

The first time the light came back on was two weeks after. The coils got replaced again (garage done this for free) and the light almost immediately came back on. Garage then replaced lambda sensor and problem went with a new error code.

Unfortunately I do not know which code the newest one is but the garage mentioned that it will have a look at the electrics. Did not make sense to me?! I am not sure what spark plugs I have but can check, should I replace them? Are there recommended ones?

I should have mentioned that the light is only coming on intermittently, goes off for a few days and comes back on if I have a number of short journeys goes off and comes back on.

Also is there anything I can look out for to see if anything has been damaged as I have been driving it for the past few weeks.

Whitesei,

The problems you mentioned were true of the car before the Lambda Sensor was replaced, since then it is running fine.

Is it fairly simple to clean the throttle body. Can probably ask my friend to do it as I am very not technical.

How much should I be looking at if it is an ECU? Where would be a place to salvage this one if it saves money. I am based in West London.

Thank you both for your help!

Gem xx

Hi Gem,

When the light comes on, does it flash and then go off? Or does it stay on? Also does it come on when you start the car from cold?

The reason i mentioned the spark plugs, is because its been known for certain spark plugs to spike the ECU resulting in ECU failure (which is often initially diagnosed as coil failure). HOWEVER, from the symptoms you describe, i would not worry about the ECU failure option yet.

Alan

Alan

Check on Fiat Forum there is a place in Bristol that someone used recently £120 or so but I cant quite remember.

A new ECU is not a good option. Very expensive and it has to be programmed for your keys or get a used ECU with keys and locks also major hassle.

See what other think but if the throttle body (TB) clean-up doesn't sort it the ECU might be the issue but dont rush that way just yet. Take the TB off the car clean it carefully with cotton buds taking care of any wire filaments and dont leave any fluff. Use carburettor cleaner or alcohol but not surgical alcohol..

Thank you to both of you again, really helping out this damsel in distress!

Alan,

The first time the light came on it flashed but it has since stayed solid. Usually stays on for a few hours and goes off. Was more prominent in the heat and in traffic. Apart from that it drives fine. No shuddering, no stalling, don't need high revs.

That is a big relief that it might not be the ECU so thank you for that.

Whitesei,

I will get the throttle body cleaned tomorrow and will look into reprogramming the ECU at one of these places. should I start a new thread to see if anyone knows anywhere?

Appreciate the help again guys,

xx

Normally ECU failure and coil failure cause the same symptoms. Which is misfiring. Often independant garages fit a few coil packs before they realise its the ECU at fault.

From what your saying, the only symptom your getting now is the EML and high fuel consumption, but no misfire? Which to me suggests the ORIGINAL fault has now been rectified.

As the EML is coming on there will be a fault code/s stored. It would make it easier for us to diagnose the potential problem if we had that fault code/s

If the code is something like "genric misfire", it could be something as simple as HT lead on its way out, as this would concur with the fault happening when the engine is hot.

without the code its difficalt really, as it could be one of many different things.

Alan

Thanks for your help again, will call the garage in the morning to get the code and post it on here.

Appreciate all the help

WhiteSei said:

A new ECU is not a good option. Very expensive and it has to be programmed for your keys..

Click to expand...

No programming needed- it's a virgin unit (plug and play in a sense). The key data is written to it when the ignition is switched on.

We've sold many over the Parts counter over the years, and all that's needed doing is the phonic wheel learn (we even give out the procedure, not that we needed to as it's been posted many times).

Hi all.

Back again.

Still having problems with engine at idol. Getting very bad now and only very high revs seems to make it move. I have been told that the ECU needs changing as when changing the lambda sensor and coils the engine management light was still on with a ECU error (not sure what the code was). Now i am not sure what I want to do as I don't want to shell out money and it not fix the problem as has happened twice already. Will a new ecu mean i will need to replace the lamda and coils again as they may have been damaged? also what is the cheapest solution to replacing ecu. I know ecu testing in nottingham charge 125 which seems good value but I dont know the hw number which they need. how do i find it out? do i have another alternative? I think i may just sell the car/trade it in and buy something else? any advice?

I'm guessing that you're in the Nottingham area, if not and you're nearer to York/Hull then you're welcome to borrow my diagnostic cable so that you can nail down the exact ECU errors

A faulty car will be worthless so selling it could the the most costly solution

These ECU repair people have been mentioned before and the seem to be good. I dont imagine they would charge for a repair that's not needed.

http://cgi.ebay.co.uk/Fiat-Punto-1-...CarParts_SM&hash=item5ad49d12d3#ht_1672wt_882

My brother uses these folks who really understand Alfas and Fiats -
Alfa Tecnico
4 Nunn Brook Rise
Sutton-in-Ashfield,
Nottinghamshire
NG172PD
01623 510 570

I am actually from the west london area. Is there anyone that knows of a good fiat specialist in this area? also how do i check the hw number on my ecu

grobinson said:

I am actually from the west london area. Is there anyone that knows of a good fiat specialist in this area? also how do i check the hw number on my ecu

Click to expand...

These the Nottingham company (Eastwood actually - where DH Lawrence lived). Easy to find - I searched "Fiat ECU" on ebay. They include all their contact details so why not phone them and discuss the problem. If the ECU is faulty, the lambda coils etc should not need to be replaced.

http://cgi.ebay.co.uk/Fiat-Punto-1-...arts_Vehicles_CarParts_SM&hash=item5ad49d12d3