looking for Prius Gen2 coolant temperature sensor location

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Which coolant temperature sensor are we talking about?

Or do you have a part # for the replacement part in question?

 

If you mean the engine coolant temperature sensor, the general location is shown in parts catalog Figure 84-04, Electronic Fuel Injection System.

The Repair Manual (more info) has a better drawing, showing its location on the side of the engine, and procedures for removing and replacing it, which consist mostly of cross-references to the procedures for removing (and then reinstalling) the inverter with converter assembly and other parts that are in the way.

 

It’s on the back side of the rad on the bottom on the passengers side.

 

Hello, and Happy 2020!

For a 2gen Prius, are the 2 coolant temperature sensors the same? D Auto P. only has one which bought, tthy offer it as the engine coolant temp sensor, but I need it for the coolant heat container "thermos" is it the same part?

Thanks.

 

They are different.


IIRC, the one on the left is for the coolant tank. I'll get a refresher later today because I'm about to replace the one on my wife's '07.

 

From page CO-3:



Excerpt attached:

 

I was right. Sensor is now replaced. Test drive went well, but it's too warm to know if the used sensor I installed under the CHRS tank will fix the P1116. It only comes up on "cold" (for FL) mornings.

@Mendel Leisk, that's an interesting find, because as @edthefox5 pointed out, there's also one on the bottom of the rad on the passenger side. So that makes three temperature sensors. WOW!

 

No. As @jerrymildred kindly mentioned, the engine coolant temperature sensor and the temperature sensor at the coolant heat storage tank are replaced with different parts. The sensor at the tank is shown in catalog Figure 84-01, Switch & Relay & Computer, under part name code 89429, part number 89429-47010.

 

They sure give tiny illustrations! But that does look right. Thanks!!

They are a little pricey new, so you might consider a used one, @Jorge P.

 

Thanks! Interesting, the guy at Advaned Auto Parts said he only had the sensor for the engine, I took the chance and bought it, it doesn't match exactly either of the 2 pictures you posted but I think it is more for the coolant heat reservoir sensor. In any case, I made the issue a bit bigger beacuse installing the sensor while the coolant was pooring out, I damaged the valve's thread, (plastic threat)

I am not sure either if the cause of the code p1150 was this temperature sensor but it is the most suspicious component to me... Here is a photo of the AAP I bought.

 

I also ordered a sensor in ebay that matches the one for the "thermos" in the mean time I am considering testing the system with the sensor from Advcd. A.P. by using a radiator epoxy to stop the leak but the snensor will become part of the plastic valve under the thermos... if that doesn't work I will have to replace the thermos and its base (valve)

 

The sensor has an o-ring and that is what seals the opening. You can't see it in my picture in post #6 because it's at the wrong angle. The o-ring sits right on the shoulder of the sensor at the nut so it seals by compression as you tighten in, unlike the one that's visible on the radiator sensor.

Edit to add: There's also no telling whether the AAP part you got is going to give the same readings as the Toyota part.

 

Thanks, I am aware of the o-ring and had transferred it from the old sensor to the AAP one, I had left the bit of teflon tape that came on the AAP sensor but something went wrong when I put the AAP sensor, maybe because of the teflon tape, the plastic thread on the thermos valve got a bit changed and now it is leaking with either sensor.

I have read in AAP sensor's reviews the it works fine, people have fixed some codes using the sensor (although I didn't read anyone mentioning the p1150 which is my case) At this point I either get the epoxy and try the AAP sensor again today or wait until the 7th. for the Toyota generic one. Will have to use the sealent anyway.

 

I would not recommend using teflon tape. It's the o-ring that makes the seal. At best, the tape does nothing. At worst, a piece comes loose and blocks a passage somewhere. Be VERY careful with the epoxy because of the same risk of it getting into the system.

And as long as the o-ring is there and has good mating surfaces, it should not matter about the threads as long as they still can be tightened. (Don't over-tighten it, though. That plastic isn't super strong.) Also, when I replaced my sensor, I had my wife hold a container under it and less than 1/4 cup of coolant came out.

If you need to replace the valve, you should be able to replace that without replacing the thermos. Same with the little housing under the thermos. I replaced my valve last spring thinking it was the source of my codes. It wasn't. But it was a royal pain to do.

 

Thanks a lot, no teflon then - the o-ring looks in fair shape but so far I havent been able to stop the leak. I do think I meesed up the valve. I am going to wait for the Toyota sensor I bought on ebay. Supposedly orininal and new but only $16... will see. I have seen the valve on ebay for $65 and the thermos with valve and sensor for $50 to $150... even if paying I little more I rather get the kit to try to avoid another leak... I will get a new o-ring if AAP has it, if that doesn't work, when I get the sensor and the time - hopefuly next week - I will give a try to the epoxy VERY carefully just by the neck of the sensor to help the o-ring..

 

Lube the O-ring, maybe silicone dielectric?

 

Yes, definitely use some lube on the o-ring. I've been using Parker O-Lube since the 1970s. Still works great.

 

Nice! thanks

 

I see some mention that a silicone dielectric grease might be detrimental to some o-rings, depending on their composition.

My moroso oil catch can has a large diameter, very thin o-ring. Moroso advises "anti-seize" grease, fwiw. I had neglected it, didn't put anything on it one time back, and it got stretched.

Long story short: after some communication with Moroso, I now have 20 spare O-rings (acquired cheap locally, they were a standard size), and have a new one installed, with a light coating of Permatex Anti-Seize (silver).

I'll see how that goes, have 19 more chances, lol.

Parker O-Lube tube in the Amazon "cart" too.