I've looked at all the threads on this topic, and I still can't find the darned thing. Does anyone have a pic to help the mechanically challenged?

 

It's a 2.5.

 

TIA!!!

First, the temp sensor is driven off of the ECU. I'm pretty sure the ECU sensor in the same spot as the 2.2, which is in the coolant crossover on the passenger side of the engine. It's under the intake manifold.

 

Here's some pics that may help

http://www.main.experiencetherave.com:8080/subaru/images/injectors/

First, the temp sensor is driven off of the ECU. I'm pretty sure the ECU sensor in the same spot as the 2.2, which is in the coolant crossover on the passenger side of the engine. It's under the intake manifold.

 

Here's some pics that may help

http://www.main.experiencetherave.com:8080/subaru/images/injectors/

 

But I read here that there are 2 sensors, one for the ECU, and one for the gauge. Is this correct?

Yes, that is correct.

 

Why do you want to replace it?

Yes, that is correct.

 

Why do you want to replace it?

 

The temp gauge doesn't move - ever. Figger the sender is the first place to look.

 

So of the two sensors in the pic, which is the gauge sender?

The one on the right, with the green on the connector, that should be the one, as the bigger one with the brown connector is for the ECU.

Thank heavens this post appeared tonight!

 

While working on my 2.2L engine swap I ran across a CEL P0115. So I will definitely use Legacy777's photos to inspect things!

 

:):):):):)

And sure enough, it was the coolant sensor. I had forgotten to plug it in when putting the intake manifold back on the engine. Everything is all good now! :cool:

Thanks Legacy777!

Hate to bump an old thread, but better than starting a redundant new one -~~ my EJ22 OBDII keeps throwing a P0115 and everything appears fine, I suspect a faulty sensor - I just scoped where the temp sensor is, it is in a tough spot - any advice on replacing this, or should I just live with it..?

It's not bad once you remove the PCV tree.

 

Be careful doing it, as it's probably old and brittle now and can crack easily. I broke mine; thank God for multiple cars! :-\

 

Once that's removed, you just need a 19mm socket and it screws right out. Keep the new sensor close by, so that when you take the old one out, you can put the new one in quick before you lose too much coolant. Coolant will spill, so have some rags handy.

 

Then just put everything else back together and you're good to go.

Thanks! Are you sure that's a 19mm? seemed smaller from a distance...

Mine was. I don't think yours is different, although it could be.

Mine was. I don't think yours is different, although it could be.

THX - does the wiring plug just pull right off the sensor?

No, there's a little latch on the harness side. BE CAREFUL with it, because it can break if you're not careful. Don't ask me how I know

 

I've been running with the wire just sitting on the sensor, and so far it hasn't moved...

Can I just remove the plug and bypass the sensor to keep the check engine light from coming on..?

No.

Because..? As long as the dash Temp gauge works, that one is unneccessary

First of it is almost more nessecary, because the ECU uses that on to decide things like fuel ratio, timing, and idle speed. You could damage the plugs, the cat, and possibly the whole engine if you run without it for a long time, as you're running rich.

 

Second, Just *bypassing* and wiring straight through would not turn off the CEL. It's not an *on/off* switch. It is a variable resistor. High resistance cold, lowers when warm but there is always some resistance. You must use a resitor to simulate the resistance value of the sensor when warm. But it has to be something. Wiring straight through would make 0 ohms. The ECU would either short out, or more likely just see this as a bad sensor.

First of it is almost more nessecary, because the ECU uses that on to decide things like fuel ratio, timing, and idle speed. You could damage the plugs, the cat, and possibly the whole engine if you run without it for a long time, as you're running rich.

 

Second, Just *bypassing* and wiring straight through would not turn off the CEL. It's not an *on/off* switch. It is a variable resistor. High resistance cold, lowers when warm but there is always some resistance. You must use a resitor to simulate the resistance value of the sensor when warm. But it has to be something. Wiring straight through would make 0 ohms. The ECU would either short out, or more likely just see this as a bad sensor.

OK that makes sense, it is running quite nicely however..

OK that makes sense, it is running quite nicely however..

 

It may not be a bad sensor. It could be the conection, in which case it would throw the code. But *most* of the time it could still be in contact and functioning. Just a momentary break in the circuit will throw the code and it won't go away till cleared or x number of starts with no problem. Just a guess

 

The thing to do is measure it's resitance across the two terminals. With engine cold. Hook up the leads of an ohmeter between the terminals of sensor. You should get a high resistance value, but something, not infinite. Set it up with clips or spade connectors or something so you don't have to hold the wires with your hands. Make sure the wires are away from the belts and start the car. As the engine warms up the resistance should start to go down. Somewhere around here someone should have the specs for the excact values. If you get Zero resistance, Infinite resistance, or no change with temp. The sensor is bad.

I have cleared the P0115 code twice, and it comes back within 60 seconds of starting the vehicle. I will probably just replace it when I get a chance, anyone know the part# - for 1995 2.2 ?

Hi. Part # should be 22630AA041 Legacy 1990-1999 SENSOR TEMPERATURE ASSEMBLY FOR 1990-1999 LEGACY ALL. Should be about $25 from an online parts dealer.

 

Not 100% sure about the '95 but on my '96 2.2L the engine coolant temp sensor is under the intake manifold tube nearest the idle air control valve. It's nearly impossible to see just looking down from the top of the engine.

 

For my '96, your P0115 shows 'engine coolant temp sensor circuit malfunction'. At least on the '96, the engine coolant temp sensor is _not_ the same as the sensor for the temp gauge, though they are near each other.