Is the Throttle Position Sensor built into the Throttle Body or separate? Maybe in subsequent years it was built in?

2005 nonturbo should be cable throttle, it should be on the opposite end of the where the cable throttle goes and replaceable.

My 2005 is nonturbo 2.5 and has the non cable electronic accelator pedal.

I understand it to be that after 2003 no more cables just dreaded fly by wire. All models. 
 

Don’t have our 2006 handy but I’m pretty sure it’s on the right side of the throttle body. 

oh right, if it's 2.5 electric throttle.  the tps is in there but not easily replaceable, you have to adjust the set screw for it and have an ecu data reader.  though, i've never heard of a tps failing on those style of throttles.  they either completely fail with the motor not working or make a terrible grinding noises if the gears are sheared.  the tps part is pretty reliable

21 hours ago, moosens said:

I understand it to be that after 2003 no more cables just dreaded fly by wire. All models. 
 

Don’t have our 2006 handy but I’m pretty sure it’s on the right side of the throttle body. 

Many 2004s are still cable as well (Legacy chassis, only Cali 2.5s and Baja turbos). But yea

Thanks for the help. The right side of the Throttle body has a plastic attachment, so the Throttle position sensor must be there inside. There is some sort of sensor on the top left. The reason for my question is that my electric accelator pedal was failing,. So I got a new one. I decided to replace the Throttle Position Sensor too and eBay found one that it said fits my car. However the sensor on the top left Throttle body is narrower and doesn't match.  Since I replaced the accelator pedal there haven't been any more problems.

1 hour ago, Ravenwoods said:

Thanks for the help. The right side of the Throttle body has a plastic attachment, so the Throttle position sensor must be there inside. There is some sort of sensor on the top left. The reason for my question is that my electric accelator pedal was failing,. So I got a new one. I decided to replace the Throttle Position Sensor too and eBay found one that it said fits my car. However the sensor on the top left Throttle body is narrower and doesn't match.  Since I replaced the accelator pedal there haven't been any more problems.

Yep, you have an electronic throttle. The throttle position sensor is built into the actuator. Replacing the sensor means replacing the throttle body. The sensor you're looking at is manifold pressure.

Just because an ebay listing says it fits doesn't make it true.

Edited July 16, 2025Jul 16 by Numbchux

18 hours ago, Numbchux said:

Just because an ebay listing says it fits doesn't make it true.

What! I can’t believe everything I read on the internet? Haha.

Here is an update to my situation. I get a 0638 code and the car coasts to a stop and the engine is still running in limp mode. The car can go about 2 mph. I shut off the engine for a minute and when I restart it runs normally again. This only happens on longer trips after maybe 30 miles and the car has been working hard. 

Apparently a dirty throttle body can be a culprit. I looked in mine and it's rather clean. Also the electric accelerator can be a cause. I replaced it and the problem did not go away. 

The next suspect is apparently the throttle position sensor. Is it true that I need to replace the entire Throttle body as the throttle position sensor is built into the throttle body?

The Diagnostic Flow chart for that (Subaru lists under P0638 to refer to P2101, so you might find more information that way) has 29 steps to it, and only the last 2 suggest replacing the throttle body. In short, it means that the ECU is asking for a target throttle angle, and the TPS reading it's getting back does not match. There are FSMs online in various places, I suggest looking it up and running through that chart for your car (FYI, the "U5" section is California Emissions)

You are correct that the "sensor" is not a separate replaceable part, as it is integrated into the actuator and motor. It's actually 2 redundant sensors.

I swapped out throttle body with another one that may or may not have a good throttle position sensor. The P0638 only shows up after about an hour of highway driving. So I took a trip today and after about an hour the P0638 showed up.

So now I would like to try a PCM from a different car to see if that cures the car. Do I need one specifically for a 2005 Outback or are there other Subarus using the same PCM?