Technical Engine won't start. Computer code P0115. What to do? [Pics]

[jlhdasMorahd]

Hi everyone. New here. 2014 Fiat 500 1.2 Liter.

Engine won't start. (it did start twice but choked very quickly)

Connected a car computer (which my nice neighbor had).

Showing this code:
P0115
engine coolant temperature sensor 1 circuit

I also checked DATA STREAM on computer:
Noticed ECT (engine coolant temp, right?) shows (engine is off, obviously, since I can't start it) 130 Degrees Celsius.
Also looked at MAP 92kPa.


Help would me much appreciated!

Please note I am not very technical - trying to figure this out because I am on a budget and I know if i'll call a tow truck to sent the car to official Fiat here - I am looking at a serious bill.

Thanks so much!

Pics

 

[jlhdasMorahd]

Update:

I am now figuring out that pic 4 shows IAT (which means "Intake Air Temp") at 18C which is correct.
But pic 3 shows ECT (engine coolant temp) shows 130C - which sure is faulty cause the engine is OFF and was off all night.
Right?
So what does that mean?

Thanks so much

 

[RobCa]

I don't know this particular car as I have a Panda but as you have had no reply, I'll see if I can help.
Like you say if ECT does mean Engine Coolant Temp then 130 is not right.
Have you tried finding the engine temp sensor and re-seating the connector? Also you should be able to find online what the approx resistance of these should be when cold and hot. If you or your neighbor has a multimeter you could then maybe check the resistance when cold. It may have gone short or open circuit.

 

[jlhdasMorahd]

I don't know this particular car as I have a Panda but as you have had no reply, I'll see if I can help.
Like you say if ECT does mean Engine Coolant Temp then 130 is not right.
Have you tried finding the engine temp sensor and re-seating the connector? Also you should be able to find online what the approx resistance of these should be when cold and hot. If you or your neighbor has a multimeter you could then maybe check the resistance when cold. It may have gone short or open circuit.

Thx, I appreciate your response.

I am most curious about which one of these two is broken (ECT or IAT/MAP).

As you said, I am assuming it's the ECT (because of the reading).

The ECT is a lower cost part (from what I can see online) but at the same time the job itself is way harder (to my understanding one needs to flush the coolant after replacement to avoid air bubbles in the system, which is above my ability).

Neighbor doesn't have a multimeter but I'll ask around.

Thx again

 

[RobCa]

You can always buy a multimeter for less than £10, Screwfix, Toolstation maybe or online. It's always handy for all sorts of jobs.
If you get one, I've measured a cold temp sensor from the panda and it's about 4 k ohm.
I've read on here somewhere that someone just siphoned out enough coolant to get it below the thermostat/sensor level rather than draining the whole system. Not sure if that applies to your engine though. Getting the air locks out can be a bit tricky sometimes, again it seems to affect some models/engines more than others.
Your other option could be to call out a mobile car mechanic. They can be very good, if you can get a recommendation. If you can prove that the sensor is faulty, you could ensure they bring out the correct part with them, or just get them to change it anyway.
Although many of these sensors are fairly universal, Fiat seem to have a habit of molding them into a model specific bit of plastic, as on my panda!

 

[eeeno]

On 2007+ Fiats the ECT sensor is on the thermostat housing and can be replaced separately or together with the housing. I'd replace the complete thermostat housing because it's a lot cheaper than buying just the ect sensor. A brand like Marelli is good quality.

You could try disconnecting the ect sensor connector and cleaning it with electronic contact cleaner and then check again the reading from obd. However this might be a symptom of something else, like a huge airbubble in the system and a headgasket leak. Nevertheless the system needs to be bled and coolant changed if it has never been done before. How about water pump? Never changed? Check the service records.

If cambelt, water pump and thermostat housing needed to be changed all at once, you could get a good deal from a garage.

 

[John202020]

Disconnect the temp sensor the car will think its cold or freezing ?

 

[jlhdasMorahd]

Disconnect the temp sensor the car will think its cold or freezing ?

Thank you to everyone who replied. I am truly grateful!

What do you mean by this? Do you mean disconnect the ECT sensor and try to turn on the engine?

 

[RobCa]

That seems to be what's suggested.
It seems the sensor reads a high resistance when cold and goes low resistance when hot. So disconnected is like a very high resistance. If the code reader thinks it's at 130 degrees when cold then it could be that the sensor has gone short circuit or there could be a short in the signal wire.

 

[jlhdasMorahd]

That seems to be what's suggested.
It seems the sensor reads a high resistance when cold and goes low resistance when hot. So disconnected is like a very high resistance. If the code reader thinks it's at 130 degrees when cold then it could be that the sensor has gone short circuit or there could be a short in the signal wire.

Thx! But from what I found on YouTube, in order to disconnect the ECT sensor I will need to remove the battery first, correct?

Any idea what is the right way of removing the batter? I have a serious fear of electrifying myself

Is it disconnecting the (-) first and then the (+)? Will that do it?

Maybe I am in over my head. Maybe I should just call the tow truck and take the heat.

 

[RobCa]

It is usually best practice to disconnect the battery before disconnecting things. For the temp sensor only, I wouldn't bother. If you do disconnect the battery sometime, you only really need to remove one terminal connection to break the circuit. The negative will be linked to the car earth/metalwork. The main thing is to avoid shorting the battery + and - and to avoid shorting the battery + to any metalwork. It's a 12 volt battery so you wont get an electric shock from it. Electric cars with high voltage batteries are another matter.

 

[jlhdasMorahd]

It is usually best practice to disconnect the battery before disconnecting things. For the temp sensor only, I wouldn't bother. If you do disconnect the battery sometime, you only really need to remove one terminal connection to break the circuit. The negative will be linked to the car earth/metalwork. The main thing is to avoid shorting the battery + and - and to avoid shorting the battery + to any metalwork. It's a 12 volt battery so you wont get an electric shock from it. Electric cars with high voltage batteries are another matter.

Thanks again. I think I understand, but I still don't know what my course of action is. Should I do what @John202020 said?

 

[RobCa]

Yes, I would try disconnecting it and try starting it. If it starts ok that would suggest its the sensor at fault. If no change then it would need further investigation.

 

[jlhdasMorahd]

Yes, I would try disconnecting it and try starting it. If it starts ok that would suggest its the sensor at fault. If no change then it would need further investigation.

So the engine can actually start and drive with no ECT sensor?

(this would help as I would be able to drive it to the garage and avoid the towing fee)

 

[John202020]

Yes it would start with the temperature sensor disconnect the car simply assumes the engine is cold unplug next to thermostat

 

[jlhdasMorahd]

Yes it would start with the temperature sensor disconnect the car simply assumes the engine is cold unplug next to thermostat

Thank you. If I take out the ECT sensor, what will hold the water from spilling out? (Excuse my stupidity)

 

[John202020]

No water will come out, just un clip the wire connector

 

[jlhdasMorahd]

No water will come out, just un clip the wire connector

Thank you for that! Any good YouTube video showing how to actually disconnect the sensor?

(trying to avoid a situation where I am after removing battery and tray yet I can't disconnect the sensor itself)

 

[John202020]

Just release/pull off the connector from the thermostat on the side of the engine(out of the brown part that stays on the thermostat)

 

[jlhdasMorahd]

Just release/pull off the connector from the thermostat on the side of the engine(out of the brown part that stays on the thermostat)

Thank you so much for the info.

I guess I will do this myself and then take the car to have the coolant replaced and vacuumed?

As I understand, replacing the ECT sensor will result in air bubbles in the cooling system.