In case you ever wondered what a new throttle body looks like, and a rant about it.

The little blobs of paint are sort of like tamper tape then? Maybe a warning label would help too.

 

Thanks for this post... While most might not be interested, those of us who had throttle body problems and pondered why have a system that can calibrated, yet can't actually be calibrated, let alone make an opportunity for serviceable parts rather than requiring the whole throttle body to be replaced?

I bet @ChapmanF has some thoughts about all this? I'd especially like to learn more about changes to Gen3 throttle body compared to Gen2?

 

I dun᠎no. The newer TB looks sleeker with both the motor and the sensor under the same plastic cover. I think I remember a recent thread where somebody opened one up and there were adjustments under there.

What seems unchanged is that Toyota hasn't ever put anything in the repair manual to suggest field-adjusting them. They just say to buy a replacement. They do the adjusting at the factory.

I'm not aware of any magic throttle-adjustment function built into Techstream. You can query the ECM for what sensor readings it's seeing, as you'd expect anyway. The repair manual also shows some voltage checks and the graph of how the two sensor outputs should track. If you were trapped on a desert island with a Prius and needed to field-adjust the TB, you might be able to, but it might be hard.

It's hard to get too worked up about tasks that might require Techstream or a comparable scan tool. There are a lot of tasks that do, and having access to Techstream or a comparable scan tool is sort of basic to being serious about taking care of a Prius.

 

the only time I see this issue with throttle body or TPS is when an incompetent shop uses a scanner that's generic. EOBD scanners will show P1121 as Throttle Body/TPS issue when it's actually the coolant control valve in the Prius world (using the appropriate scanner) The 425k miles Prius that I recently bought has a print out from a parts store showing TPS codes (and I can see wiring insulation holes on the terminals that show the previous mechanics were wire probing it) I know at that point that the guys tinkering the Prius are using the wrong tool. Oil is also going into the throttle body due to bad pcv but it rarely fails.. It's usually bad diagnosis from mechanics or the use of wrong scanners.

 

Yes... That's true... However the Gen2 I replaced a throttle body on had the usual bad sensor in the coolant control valve and that wasn't a diagnosis with a generic scanner. Perhaps there's some kind of electrical interplay in those circuits beyond just using a scanner without hybrid codes in its library?

 

That just comes down to P1121 being, like all P1 codes, manufacturer-defined. In five different cars it can mean five different things, whatever the manufacturers had in mind.



A generic scan tool that has any description for P1121 baked into it is going to be wrong on every car except whichever one that description is right for. The code has nothing to do with a throttle issue on a Prius, just like it has nothing to do with a coolant valve on some other car where it means something else.

Some scan tools will show you the code and sort of all the meanings it's known to have across different cars, so it might show up as "P1121 throttle sensor or coolant control valve", but that's as confusing as it is helpful, and could give people the wrong idea that the two things have something to do with each other.

Really, the best thing for any generic scanner to do with a P1 code is just show you the code and say "look it up in your own car's repair manual", which is the sure-fire way to get the right answer for what a P1 code means in your own car.

This sounds more like a car that had two problems. There isn't electrical interplay between those components.

 

Yea... That's it right there! The first line of every P1 code should say "Manufacturer Defined" but the businesses who make scanners want to pretend that their products are smarter than that, which make 'em look dumb.

Which scan tool presents all the different meanings across different cars for the same code?

 

Not sure I know of a specific product. I've seen people post agglomerated code descriptions like that in questions here, so either they were using a tool that gave that description, or they googled the code and did their own agglomerating of all the results they got.

So instead of 'will', maybe I should have written 'might'.

 

Read up on installing Xwindhorse or windhorse driver that can help sometimes