pilottodd2

murphysf

From what I understand there are 2 or 3 coolant temperature sensors. I believe one is just for the gauge and then another is for the ECU. The one I think is being flakey is the one for the ECU, that would be the one telling it if it up to a certain temp within a given amount of time, not the dash gauge.

It only threw the code twice in the last two months so it is intermittient. When I was getting data from the ECU there was no code everything was fine.

here is a good video that talks about the sensor that I think is being intermittient


and here is another good video that shows the 2 - 3 temp sensors.


and more good videos

salimshah

There is a thermal switch ... bottom of the radiator which kicks on/off the cooling fan and one temp sensor [the one you are referring to] .. this one feeds the ECU and the temp gauge in the cluster.

It is hard to trouble shoot when things are working.
Salim

murphysf

I am sorry salimshah but you are incorrect, there are two sensors on the passenger side right next to each other, located just beyond the top hose. One is for the EFI and the other is for the dash gauge. The 3rd sensor is located near the thermostat lower hose (drivers side) this 3rd sensor is the one that turns on the radiator fan.

murphysf

the sensor for the dash gauge has nothing to do with the EFI / ECU , or any codes.... same wiht the fan sensor / switch...

I think my problem is a flakey readout of the sensor that feeds the EFI

salimshah

I welcome the correction.

Salim

murphysf

P0128 reappeared again, last time this happened was three months ago. Like last time I cleared it and has yet to come back after 3 days of driving.

This is the third time it has happened first time was back around March, then three months ago and now this past weekend.

The conditions this time was, I started the vehicle up cold at 11pm and got immediately on the freeway, after a few minutes of driving it came on. I stopped and cleared it and it hasn't returned.

I am thinking to replace the coolant temp sensor that connects tot he ECU.

Ideas?

MedicalDoc

Yes, do that and report back.

murphysf

will do, I just ordered a sensor off ebay but it is coming from japan so won't see it for about a week..

murphysf

code came back again, this time about 20 days later.

conditions - I started the car at around midnight (temp was around 53F) and immediately got on the freeway and after about 5 or so minutes of driving it came on.

The temp sensor that I ordered earlier in the month arrived last week so I changed it today...

stay tuned.

trips1

Can you please update if the error went away permanently after replacing the temp sensor?

murphysf

Code never came back after I changed the sensor 7 months ago.

trips1

Thanks. I will appreciate if you can please give me the part number or the link to the ebay item. Also any comment on the level of difficulty to change it myself?

Also i am hoping there is no hurry to change it and i can take my time for it and do it whenever time permits.
The coolant was changed about 2 years ago and my temp gauge has never shown any sign of overheating.

murphysf

part number is 89422-35010

its super easy it took less than 5 minutes. Order the part and just do it.

Do it when the vehicle is cold , let it sit overnight and therefore the cooling system won't be pressurized, I lost very very little coolant didn't have to add any or top off. Have the new sensor ready and one your remove the old one remove the washer off it and put it on the new one and thread it in by hand .

You will need a deep socket, I forget what size.

The sensor under discussion does not feed the temp gauge, the temp gauge is a separate different sensor. The sensor I changed was the one that only connects to the ECU (engine control unit). It was starting to fail and intermittently sending the wrong value to the ECU which caused the code I was getting.

Don't over think it just order the part and swap it.

murphysf

socket to remove sensor is 19mm and it needs to be a deep socket.