Hi,

I seem to have a similar problem to a number of threads. Car suddenly needs 7/8 attempts to start from cold. RAC diagnostic - P0115 - Water Temp. sensor problem.

I replaced sensor, it made no difference, have tried cleaning earth points - leaving battery disconnected for over an hour while doing so, car now start after 2/3 attempts.

Car was subsequently re-diagnosed with exactly the same P0115 issue.

I have read threads regarding MAP sensor; software updates, etc, but I'm not sure which way to go, particularly as dealer is wanting to charge for another diagnostic and potentially a new ECU!!

Any suggestions which way I should go?

Definitely sounds like your MAP sensor. Happened to mine. I bought one off eBay and replaced it myself. £25. None of the garages I went to knew what it was either. Seems to be a common fault with the GP.

jjr0305, thanks very helpful, £25 seems worth a punt!

I note there is a guide to replacing the sensor on this forum, did you use that?

It seems straightforward, but when I tried to get to the sensor to see if it was fouled, I couldn't get the wiring harness connector off - how hard do you need to pull?

Also, did you use a FIAT part / how do you know which part to get?

Samuel87 said:

jjr0305, thanks very helpful, £25 seems worth a punt!

I note there is a guide to replacing the sensor on this forum, did you use that?

It seems straightforward, but when I tried to get to the sensor to see if it was fouled, I couldn't get the wiring harness connector off - how hard do you need to pull?

Also, did you use a FIAT part / how do you know which part to get?

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Did you press the clip in to release it?
Some early gp's use a different set up you will find a Bosch part number on yours to I'd which you have

Thanks Andy, when I tried, the connector it seemed to have a yellow slider type mechanism which doesn't appear to do much, a little afraid that simply yanking at it might wreck the connector!

I assume that the parts number will be on the sensor - there appears to be lots of different sources on-line, does it matter what make of part I buy?

I didn't buy the Bosch one and it works no bother. As long as it's the correct part, the manufacturer shouldn't matter. As far as I'm aware anyway.

And yeah I remember mine being a bugger for getting off. Just be patient. Slide the clip and just pull on both sides. It'll eventually give. Make sure the battery is disconnected whilst doing it, and leave it off for an hour afterwards.
When you put it back on take it for a long drive to get the car used to it.

As you suggested I gave it ago and I managed to get the connector off and the sensor out.

It's very clean - as I'd expect for a 38K car, so I was able to identify the part number but can only find it for around £36. Anyway I've stuck it back in and reconnected the battery so I can use it until I can get a replacement.

The originals a Bosch, where did you get your replacement part?

I got it off eBay on a Buy It Now. Brand new too. I must have struck lucky, but £35 is still a load better than some dodgy mechanic replacing the ECU for hundreds

Samuel87 said:

As you suggested I gave it ago and I managed to get the connector off and the sensor out.

It's very clean - as I'd expect for a 38K car, so I was able to identify the part number but can only find it for around £36. Anyway I've stuck it back in and reconnected the battery so I can use it until I can get a replacement.

The originals a Bosch, where did you get your replacement part?

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I got mine off eBay from the air flow monitoring company come with 12 month warranty too

It might look clean but oil and fuel vapor degrades it internally

Andy, I tried your suggestion - out of stock for a couple of weeks -but £20 + postage which doesn't seem at all bad.

In meantime the Local Fiat dealer has agreed to look at ECU and tell me if it is of the type which would accept an update - I'd still need to pay for any update to be done - but, no one seems to know what, if anything this might do to resolve the problem.

Will post to let everyone know what happens.

Samuel87 said:

Andy, I tried your suggestion - out of stock for a couple of weeks -but £20 + postage which doesn't seem at all bad.

In meantime the Local Fiat dealer has agreed to look at ECU and tell me if it is of the type which would accept an update - I'd still need to pay for any update to be done - but, no one seems to know what, if anything this might do to resolve the problem.

Will post to let everyone know what happens.

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Got a card through my door saying my local dealer are doing "free" computer updates to cars the other week and a free health check

Andy,

I have been in contact with Fiat customer service to see if this offer was local or across the dealer network, they haven't got back to me yet.

Bizarrely the car seems to have responded to the good weather and has started on 1st or 2nd attempt over the past few days!

Will be getting MAP sensor when available and will see what "Fiat Central HQ" have to say before looking at update.

Fingers crossed that both car and weather continue to be good!

Samuel87 said:

Andy,

I have been in contact with Fiat customer service to see if this offer was local or across the dealer network, they haven't got back to me yet.

Bizarrely the car seems to have responded to the good weather and has started on 1st or 2nd attempt over the past few days!

Will be getting MAP sensor when available and will see what "Fiat Central HQ" have to say before looking at update.

Fingers crossed that both car and weather continue to be good!

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What is your battery condition like? A bad battery can also cause this issue most fast fit places do "free testing". Try a few.... Watch it as they obviously have the push a new battery on you mentality a good one should be honest........

Samuel87 said:

Bizarrely the car seems to have responded to the good weather and has started on 1st or 2nd attempt over the past few days!

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That will be because the (incorrect) reading from the air temp sensor is not as far out as it would be when the ambient temp is lower.

I'm really surprised your Dealer doesn't know about the common air/coolant temp feasibility error issue, and in any case- 5 mins spent actually looking at the ECU parameters and it would be obvious that the air temp shouldn't be stuck at over 40degC constantly. I despair at how bad/lazy some Tech's are these days. :bang:

The ECU reflash will most likely be for the "Excessive Rad. Temp" error on start-up caused by the ECU not being programmed correctly for low battery voltages. Depending on the ECU version number, some can be updated, some need the ECU replacing. However, this fault will not have the effect on start-up that you're experiencing.

D4nny8oy said:

That will be because the (incorrect) reading from the air temp sensor is not as far out as it would be when the ambient temp is lower.

I'm really surprised your Dealer doesn't know about the common air/coolant temp feasibility error issue, and in any case- 5 mins spent actually looking at the ECU parameters and it would be obvious that the air temp shouldn't be stuck at over 40degC constantly. I despair at how bad/lazy some Tech's are these days. :bang:

The ECU reflash will most likely be for the "Excessive Rad. Temp" error on start-up caused by the ECU not being programmed correctly for low battery voltages. Depending on the ECU version number, some can be updated, some need the ECU replacing. However, this fault will not have the effect on start-up that you're experiencing.

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does that mean im wrong about the battery

remember replacing my MAP then the problem "coming back" shortly after banging a new battery on and it behaved then

Andy Monty said:

does that mean im wrong about the battery

remember replacing my MAP then the problem "coming back" shortly after banging a new battery on and it behaved then

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Not necessarily, Andy. The battery on the 1.2/1.4 is marginal at best, and the voltage drop on colder days can cause all sorts of weird occurances (the starter motor "dropping out" and re-engaging while cranking being one of them).

Been a bit distracted Dad's Alfa blew it's top - he thinks it could be the turbo, so had to act quickly to try and resolve the GP's issues so we have at least one working motor!

So in it went to our local Fiat dealership, they agreed to check whether the ECU would accept an update and - after referring to your comments - added that their was a chance that these would resolve the problem.

Anyway to cut along story short, we appear to have been lucky - the ECU has been updated and, so far - 4 days - the cold start problem appears to have disappeared!

I must say that the dealer also gave the car a full health check and topped up fluids and cleaned the car, so not bad for £42.

Thanks for all the help, I will bear in mind the MAP sensor advise if problems reoccur.