Were new panda owners, she's got less than 5K miles and registered in 2008.

Intermittent fault has started occurring. Its frequent and causes the engine to cut out at idle and judder when driving but it only happens every 1-5 minutes. Engine management light flashes up but does not stay on long enough to pick up a fault with my laptop OBD reader.

Had a mobile mechanic look into this and previously the fault light stayed on. The mechanic got a P0606 (PCM/ECU fault). He checked and cleaned contact and diagnosed a new ECU recommending i should take it to a fiat dealer. I decided against taking it to Fiat due to the high cost

I've now purchased a new ECU and coil packs and was ready to fit however can't get the fault light to stay on so i'm not convinced its either of the parts

I've had the laptop on and can't see any problems showing on the sensor reading however i'm an engineer but not a mechanic

Anything else i can check with the laptop before i go to the expense of fitting? I'd be gutted if it wasn't fixed after fitting the parts

Thanks for any help

Dave

Welcome to FF.

Its very Vuage and could be anything electrical tbh. I doubt that it's ECU or coil pack failure though.

Where did you get the new ecu from out of interest

Jon.

ECU's can be tested by any number of independents for £35 or so, and is presumably the wisest move before replacing them at huge expense.

I guess you've checked every electrical connection you can find under the bonnet?

Got the ecu from auto flash. They have a shop on on ebay.

Can't post a link as i have less than 5 posts but search for Brand New Fiat / Alfa ECU's - Engine Control Unit if interasted

Very helpful guy called Aron. He can also test the ECU's but the car is still being used at the moment by the wife and baby so can't have it off the road for too long

I've checked electrics. Thanks

Panda newbie said:

Had a mobile mechanic look into this and previously the fault light stayed on. The mechanic got a P0606 (PCM/ECU fault). He checked and cleaned contact and diagnosed a new ECU recommending i should take it to a fiat dealer. I decided against taking it to Fiat due to the high cost

Click to expand...

So the mobile guy said take to Fiat dealer but you thought no....

Yes you can get ECU's tested but if the fault is intermittent it might not show up at time of testing unless it was tested over a period of time and under different conditions.

Didn't take it to the fiat dealer as we've only just purchased the car so can't really afford it. If it is the ECU i can replace it myself. I was quoted just under a grand for a new one from a main dealer.

QUOTE]Yes you can get ECU's tested but if the fault is intermittent it might not show up at time of testing unless it was tested over a period of time and under different conditions[[/QUOTE]

I thought that would be the case. I guess it would be difficult to diagnose unless a component is visibly worn.

i replaced the coil packs today and took it for a 20 min drive. So far the fault hasn't occurred. Not convinced that was the problem and i only purchased them on advice from ECU guy who said it could take out the new unit if the pack has a fault. Will have to see how it goes

If i did have a problem with bad connection/coil pack would it cut out on the engine management immediately or would it just sound lumpy and run on three cylinders for a second or two before cutting out?

It's a twin coil pack waisted spark setup so would only run on 2 if a faulty coil.

What if you change the coils (which you have already done) and the ECU...and the fault is still there? (which I suspect it might be)

Well as i mentioned earlier the mobile mechanic was convinced it was the ECU. If it's none of those thing's i'll probably have a little cry.

Do you have any other suggestions for things i can test out with laptop or tests? I'm a mechanical engineer with good electrical skills and access to electrical meter, meggars, infrared thermometers and various other tools.

The cars only 3yrs old with less than 5k on the clock and a full service history so i'd hope that would limit the possible faults

Edit: Any advice on testing the coil packs would be helpful what is the procedure and what should the resistance be? I have a meggar so can also test insulation resistance

I would be looking into the vehicles history, good chance car was traded in with this fault and coils, ECU might of already been changed without success? First rule of any diagnosis get as much information as possible.

Car was doing approx 1k every year according to service log. Suspect it was owned by an older gentlemen for popping to the shops. I purchased from a established trader. It ran fine for approx 200 miles/ 2 weeks but then dramatically the intermittent fault started to occur (every 1-5 mins). I don't think the fault was hidden and I've no reason to suspect the ECU has been replaced.

Why do you suspect the coil pack and ecu has been replaced previously? You mentioned before that you didn't think it was either so why would someone else think differently?

Can you advise me on bench testing the packs?

Just put my meter across them
LT side reading the same on both at 0.59 Ohms
HT side reading 6.77 KOhms on one and can't get a reading off the other even with a meggar set at 1000v.
Does the 6.77KOhms sound about right?

The cars ran fine for 2 weeks/100 miles so seems to be fixed.

The new coil packs gave resistance reading similar to the readings above. Hope this helps someone in the future.

Thanks for all the help and advice

Panda newbie said:

The cars ran fine for 2 weeks/100 miles so seems to be fixed.

Click to expand...

Hope so....but I would give it a few months yet

hi, glad it seems to be running well now,

as mentioned earlier;
the coil pack itself should'nt make it stop altogether..,
perhaps you had a weird /bad connection in a loom , that got straightened-out while swapping coil-packs,
hope it lasts,
good luck,
Charlie