Technical Panda fault codes: P0504, P0300, P0302, P0303. With the latter 3 saying temp too high

[Elliott 4]

Fiat panda has been misfiring intermittently. The first three times the system injection symbol was static and I was restart the engine within a couple of minutes. When this happens I can be driving along at any speed and it all just cuts out with no drive ability. The next two times the warning symbol flashed (orange symbol) and it took 40 minutes for me to be able to drive it again. The last two times the warning symbol was flashing and this correlated with it being more serious, as in longer wait for restart and the engine could be heard misfiring.

The garage fitted a new coil pack and leads ( twice because they thought that the first one was perhaps faulty).

It went to car electrical experts today but the car behaved itself when the drove it up and down the road. They wondered about a faulty ecu as a guess. Can anyone help?

P.s. this have put me off the fiat panda - I previously had a gear box fail on this very car!

 

[Elliott 4]

‘Has’ put me off

 

[MrMagoo]

Have you changed the spark plugs?

 

[Goudrons]

Not sure how true this is, but your old coil pack could have shorted out the ECU.

 

[Elliott 4]

Thank you for your responses.

Following on from what the AA chap said, I asked the original garage if they could put new spark plugs in because the AA chap said to me that he always changes the spark plugs when putting in a new coil pack, but the garage said they would have a look at them, but they didn’t think they needed changing. It then went onto an electrical car place and he seemed to think that the fault wouldn’t be intermittent if it were the spark plugs (I think that’s what he said anyway). This is so difficult.

 

[Elliott 4]

P.s. if the old coil pack could have shorted out the ecu would the fault be intermittent?

 

[Elliott 4]

Not sure how true this is, but your old coil pack could have shorted out the ECU.

That video is very good thank you. The hardest thing will be asking the garage if they have/could run the same checks without them taking offence.

 

[Goudrons]

Have you the old coil pack and a multimeter?
That would be a good place to start.
If the coil pack doesn't pass the test, there's only so many parts before it and after it to have checked.

With regards to the an ECU fault being intermittent, it's possible I suppose.
A crack or break in a circuit might alter with heat or vibration.

Then of course you have the wiring between the coil and ECU.
Some earlier models (the 169 with 1.1 engines) did have iffy wiring in the loom from the ECU to the coil.
If a short has damaged the wiring, again heat and vibration could effect it.

Looking at Youtube again, there are a few posts (mainly 500's but the engines and engine harnesses would be the same) regarding wiring faults from the ECU to injectors and/or coils causing similar misfires and DTC's.

Perhaps your auto electrician could test the wiring to the coils and injectors before you spend out on having the ECU tested.

 

[Elliott 4]

Have you the old coil pack and a multimeter?
That would be a good place to start.
If the coil pack doesn't pass the test, there's only so many parts before it and after it to have checked.

With regards to the an ECU fault being intermittent, it's possible I suppose.
A crack or break in a circuit might alter with heat or vibration.

Then of course you have the wiring between the coil and ECU.
Some earlier models (the 169 with 1.1 engines) did have iffy wiring in the loom from the ECU to the coil.
If a short has damaged the wiring, again heat and vibration could effect it.

Looking at Youtube again, there are a few posts (mainly 500's but the engines and engine harnesses would be the same) regarding wiring faults from the ECU to injectors and/or coils causing similar misfires and DTC's.

Perhaps your auto electrician could test the wiring to the coils and injectors before you spend out on having the ECU tested.

Thank you for all of that information. As far as I’m aware he has checked the wiring because I asked about the possibility of a loose connection. To my mind it didn’t sound like he actually tested the ECU because he said a faulty is ECU is a guess, but because the car behaved itself we are not sure what’s wrong. I asked about the spark plugs as well, but I can’t be certain what he said in that regard.

 

[Elliott 4]

Thank you for all of that information. As far as I’m aware he has checked the wiring because I asked about the possibility of a loose connection. To my mind it didn’t sound like he actually tested the ECU because he said a faulty is ECU is a guess, but because the car behaved itself we are not sure what’s wrong. I asked about the spark plugs as well, but I can’t be certain what he said in that regard.

With regards to the old coil pack the garage first replaced it in October and I saw them put it in their car parts bin so I can’t imagine they would still have it after all of this time. It’s a pain

 

[Goudrons]

Everything is a guess at the moment, it requires some methodic investigation to narrow the problem down.
There isn't much more I can help you with, just make a few suggestions.

As it's intermittent, is there anything that's common to each episode?
Certain rpm or road speed, bumps in the road, weather, anything?

How often does it misfire?

When it's not misfiring, does it run ok, not down on power or anything?

If it's running ok now, can you alter this by wiggling the loom from the ECU to the coils and injectors?
If you remove the connector from the ECU to the coils/injectors do the pins look straight, is there any blistering or signs of heat around the terminals, are they all clean, does it refit smooth and snug?

 

[varesecrazy]

Hi

All good advice above

I will ask... are the Coolant and Oil levels holding properly?

Charlie

 

[Elliott 4]

Everything is a guess at the moment, it requires some methodic investigation to narrow the problem down.
There isn't much more I can help you with, just make a few suggestions.

As it's intermittent, is there anything that's common to each episode?
Certain rpm or road speed, bumps in the road, weather, anything?

How often does it misfire?

When it's not misfiring, does it run ok, not down on power or anything?

If it's running ok now, can you alter this by wiggling the loom from the ECU to the coils and injectors?
If you remove the connector from the ECU to the coils/injectors do the pins look straight, is there any blistering or signs of heat around the terminals, are they all clean, does it refit smooth and snug?

Sorry, I’ve only just seen this. I don’t think it’s RPM or bumps as I drove around on the estate where the electrical garage is today in the hope that it would play up - lots of wheel turning and speed bumps. I thought it may be to do with speed, but the garage said that they drove it 6/7 miles and it reached 50 at one point (no motorways where I live). I also drove it home so that’s another 7 miles. It should have played up by now. I did wonder if, when they were checking everything, could they have tightened a connection when they were checking it all through, but didn’t realise because it wasn’t overly loose?

I would worry about taking out the ECU in case I didn’t get it back in okay. I’m a actually a woman and know nothing about cars but I’m just trying to apply a logical approach.

I have a multimeter and I did wonder about following that video that you sent me.

You’ve been brilliant- you really do know your stuff. Thank you

 

[Elliott 4]

P.s. it doesn’t drive that well. It’s not smooth and heavy on the steering. They said their 2006 panda (mines a 2012) drives better than mine. Interestingly, when they replaced it with a second brand new coil pack it drove really nice on the way home, but I was back to square one the next morning.

 

[Elliott 4]

Hi

All good advice above

I will ask... are the Coolant and Oil levels holding properly?

Charlie

I assume so, but if it were that would it be intermittent? I would have thought that it would gradually get worse as the levels drop further?

 

[Panda IIs]

I assume so, but if it were that would it be intermittent? I would have thought that it would gradually get worse as the levels drop further?

Maybe there's a sticky injector; you could try a fuel additive (not cheap, but my experience is that it does enhance things generally)? As stated, its all guess work based on your descriptions. Fault codes indicate there is something wrong, not the root cause, so, as mentioned, a methodical approach is required to eliminate the functional parts and isolate the failure.

ECU issues are often blamed (a bit of a cop out) but are rarely the case, in my experience.

 

[varesecrazy]

Worth a look NOW ;-)

Coolant is the main thing that 'kills' these engines..
if the level drops too far the engine overheats... bills can be pretty big


Dont let your lack of car knowledge put you off... weve got a fair few panda and 500 owners who 'arent blokes'.. but love the cars and have picked up many tips on looking after them

@Lorna87 has been nursing her Panda along for a few years now

@Baglady1990 could put a lot of us to shame with her determination to keep her money going into her Cars and Self, rather than the mechanics 'Holiday Fund'


Dont be afraid to ask

Charlie

 

[Goudrons]

So it's stopped misfiring, at least for the time being?

Have the warning lights been reset on the dash, are they still off?

It might be a wiring or connection issue as if they have disturbed the connection/wiring, so it might be ok for a while.
There have is plenty of evidence that Fiats wiring from the ECU to the coils/injectors on these, the 500 and the previous model Panda is a bit suspect.

From what I read about how it drove after they fitted the new coil, it does perhaps lean towards a problem with what signals the coil to work.

Another comment you made is the heavy steering.
Has it always been like this?
The steering it electrically assisted and very power hungry, if there's a fault with the battery or vehicles charging system it does tend to cause the steering motor to play up.
Perhaps a fault with the charging system or electrical system is effecting the signal through the coil or injectors.
The older models are prone to the earth straps from the engine to the body rusting out, that could cause various circuits to try and find an alternative earth and cause those systems to play up.

 

[Elliott 4]

So it's stopped misfiring, at least for the time being?

Have the warning lights been reset on the dash, are they still off?

It might be a wiring or connection issue as if they have disturbed the connection/wiring, so it might be ok for a while.
There have is plenty of evidence that Fiats wiring from the ECU to the coils/injectors on these, the 500 and the previous model Panda is a bit suspect.

From what I read about how it drove after they fitted the new coil, it does perhaps lean towards a problem with what signals the coil to work.

Another comment you made is the heavy steering.
Has it always been like this?
The steering it electrically assisted and very power hungry, if there's a fault with the battery or vehicles charging system it does tend to cause the steering motor to play up.
Perhaps a fault with the charging system or electrical system is effecting the signal through the coil or injectors.
The older models are prone to the earth straps from the engine to the body rusting out, that could cause various circuits to try and find an alternative earth and cause those systems to play up.

Yes when they put the first coil pack in it happened weeks apart and when they put the next coil pack in it happened on two consecutive days - the warning symbol was flashing on these two occasions, whereas in the past they were static. I drove around for at least 30 miles today and the chap at the electrics place drove it this morning for 6/7 miles, but nothing. It’s bound to happen again though surely?!

No when it happens I turn the engine off and the symbol disappears when it’s able to be driven again.

If I’m honest with you I can’t really remember when I noticed the steering, but noticed a marked difference in the drivability when coil pack number two was put in, until the next day when the drivability was rubbish again and then it cut out about 5 miles away from home.

Once again you have been brilliant- you really know your stuff. Do you do diagnostics/repairs, if you don’t mind me asking? You probably live too far away though and the danger would be that I may not make it to you!

 

[Elliott 4]

Worth a look NOW ;-)

Coolant is the main thing that 'kills' these engines..
if the level drops too far the engine overheats... bills can be pretty big


Dont let your lack of car knowledge put you off... weve got a fair few panda and 500 owners who 'arent blokes'.. but love the cars and have picked up many tips on looking after them

@Lorna87 has been nursing her Panda along for a few years now

@Baglady1990 could put a lot of us to shame with her determination to keep her money going into her Cars and Self, rather than the mechanics 'Holiday Fund'


Dont be afraid to ask

Charlie

Cheers Charlie. Water level was lower than usual, but maybe I just slipped in topping it up. Topped it up and I will keep an eye on it.