How many Coolant Temp Sensors?

2005 legacy non turbo. I found only one coolant temp sensor it is on the water pipe can see it from front of the vehicle, left of the generator.

If I unplug it temp gauge goes max high.

Question: does this model has one coolant temp sensor or two (one for gauge another for computer)?

If two, there is second, I looked all around water pipe, could not find it.

Thanks.

From what I'm reading in the service manual, it looks like that is the only coolant temperature sensor.

Thanks.

My radiator fans are always on, if I unplug the temp sensor should the fans turn off?

I don't know enough about the cooling system to say, so hopefully someone else will chime in to help.

 

My guess is that if you disconnected the sensor, that might cause the car to go into a fail-safe mode and cause the fans to always run. I'm wondering if the coolant temperature sensor you have now is bad, and that's why the fans are always on now.

 

I did come across the following threads which you should check out. It looks like the turbo legacies had a similar problem, and after skimming through those threads it looked like a relay was the problem.

 

http://legacygt.com/forums/showthread.php/cooling-fan-relay-issue-now-recall-campaign-55332.html?t=55332

 

http://legacygt.com/forums/showthread.php/cooling-fan-always-running-143216.html

 

http://legacygt.com/forums/showthread.php/cooling-fan-stuck-oni-10568.html?t=10568

Thanks for the links,

changed relay fans are still on, don't want to change ECU (too much).

Guess will have to live with it, may disconnect fans during winter.

If I were in your shoes, for $10 I would try replacing the coolant temperature sensor. I think the part number for your car is 22630AA17A, but I would double check that if you do give it a try.

the fans run when the engine is cold? does the water temp sensor show cold when engine is cold?

 

is your a/c on ?

 

if the sensor is un plugged the fans turn on is a safety mechanism as its safer to assume the engine is hot

 

you can do a number of things like putting a coolant temp switch in the heater core hose that could be used to turn the fan on.

 

fyi you can purchase a new ecm on ebay i bought one a awhile back for 60$ for a 2.5i

"the fans run when the engine is cold?" Yes

"does the water temp sensor show cold when engine is cold?" Yes

 

"is your a/c on ?" No

 

if the sensor is un plugged the fans turn on is a safety mechanism as its safer to assume the engine is hot

 

"you can do a number of things like putting a coolant temp switch in the heater core hose that could be used to turn the fan on. " Inside rubber hose, not metal water pipe?

Since fans run all the time, thermostat never opens.

I unplugged the fans and let car run for 10min, only then thermostat opened.

 

"fyi you can purchase a new ecm on ebay i bought one a awhile back for 60$ for a 2.5i" I will look for it.

Thanks.

^ you can put the temp switch on a heater core hose those flow all the time.

 

i'm not certain but the actual part that likely fails in the ecm is a 0.42$ part that could be changed by anyone who would play in that sort of thing.

 

the fact that your temp gauge sweeps means the sensor is working.

 

call up subaru there may be a recall about this issue i remember hearing of it before.

 

another question do the fans run when ignition on and engine off?

"the fact that your temp gauge sweeps means the sensor is working."

thought so, it does show correct temp

 

"call up subaru there may be a recall about this issue i remember hearing of it before."

did it, they said no recall for mine, even though where was a recall for same year turbo model.

 

"another question do the fans run when ignition on and engine off?"

yes, just draining the battery:(

Finally went to auto-zone fore codes

P0118 Engine Coolant Temperature Circuit High Input

so is it the temp sensor o computer?

P0500 Vehicle Speed Sensor two of them

have to replace both probably

 

^ the p 0118 is probably when you unplugged the sensor.

 

the p 500 could occur on an automatic if you push the car in N with the key on and engine off.

is the car auto or manual?

It is manual,

engine and abs lights were on when I got the car,

talked to the mechanic who took care of it for previous owner

he said lights were on for a years:)

p500 looks like a wheel speed sensor.

 

if you use e built in code reader in your car it wil give you a c code c meaning chassis code

Will call auto-zone if they can read chassis codes,

do you need to drive the car to get those codes?

your car has a built in code reader you do not need anybody or any tools.

Ha, did not know,

downloaded service manual, reading.