Bad mechanic? P1121 = Throttle Pedal Position Sensor?? did they mix up P0121?

The code reader the mechanic used has an outdated library that doesn't have prius-specific hybrid codes Their scanner told them throttle position throttle position sensor when P1121, whereas a competent shop with an updated error code library would of seen P1121 - coolant control valve. They owe you a refund for fixing something that's not broken... If you google "priuschat throttle position sensor" you'll find numerous examples of people on here making the same mistake.

As for the catalytic error codes, maybe they damaged the O2 sensor wires. Or worse than that, you might want to see if you now have a cheap aftermarket in place of your original OEM cat if you had one? This would indicate they stole a $1K worth of precious metals in your OEM cat that keeps the exhaust super clean. And in your state that amount of theft is considered a felony.

And if that happened, you might want to file a police report and have a copy of it in your pocket when you attempt to give them an easy way out to satisfy you or you become the customer who was a little too smart for all their dumb scams and got their business shut down and their employees contemplating the likilhood of a felony conviction/jail time.

 

There's no way that the sensor in the coolant control valve failed that quickly... So either your kid who did the job had made a mistake, or the part you bought was defective. And I'm sure your kid will love to know that you'd like him to find out which one...

As for the motor mount, it used to be standard practice to show the customer the damaged part to prove their diagnosis... If they didn't show you the part you got their 3rd strike. As in motor mounts are what a lazy mechanic blames on a rough running engine, but the nature of a Prius engine makes that claim ridiculous. And it is true that motor mounts can wear out on super powerful engines, but on a low powered economy hybrid without misfires/blown head gasket or bent rod... Nope!

 

PS: Here's coolant control valve I buy online and have worked well for me: https://www.ebay.com/itm/394097566363

 

If you have no cabin heat, I would first check the coolant level in the radiator (Not just in the overflow tank) when the car is cold.

P1121 is a problem with the 3-way coolant valve position sensor circuit. It's possible to have something wrong with the related wiring, but I have never seen or read about that happening. It has always been a "bad" valve.

Yes, your O'reilly valve is likely bad. I have been burned by aftermarket parts that were faulty out of the box - many times over the past 30+ years.

In general, the most reliable repair is to install a genuine Toyota part from a dealer or reputable online source (not amazon, ebay, etc).

If the heat worked before and suddenly is cold, I would suspect that the coolant valve is the cause.

I can only speculate about that shop. It would seem that they use a "cheap" scantool that doesn't have correct definitions for OE specific codes (such as any P1xxx code). They don't have or use service information that would provide details about the proper code and testing procedure, or the TSB's Toyota released about it.

(Willful) ignorance is unacceptable, especially when it comes to auto repair. I wouldn't go there.

Posted via the PriusChat mobile app.

 

And this is why I have at least two of these cars at present I have five family members are in them so there is never any knee-jerk reaction to listen to ignorant nonsense from people that may not have a clue It also gives me time to do the research I want to do the car's sitting right here in front of me not going anywhere I've got five more on staff to drive always have an extra mode of transportation so that when something arises with one of them you can confidently and comfortably sort out the issues on your own time if you will some people work and research slower than others and because you're driving an old car like an '09 all of this stuff is out in the wild there's nothing that's going to happen to your 09 that hasn't already happened before. But that doesn't make shops progressively smarter lots of shops do not embrace technology they want to work on hellcats and old Dodge chargers and muscle cars and what have you their mentality as you can take that piece of poo poo hybrid electric thing he over to the Toyota dealer or to some of those computer nerds that like to spend a lot of time on the computer reviewing what might be wrong or what might need to be done as opposed to picking up wrenches. A lot of these places today are what you see on Facebook videos bunch of loud talking people who think they know everything You want to avoid this kind of nonsense at all costs You just wind up burning money once you money leaves your hands and parts leave your car getting people convicted of a felony and stealing a part off your car doesn't do you any good because you're sitting there with your car fubar all the time you're waiting for your resolve that could take some time. But if you have another mode of transportation then that car can be parked and you can wait or do whatever when you don't have that option you're under the gun and you make bad decisions.

 

It's not even so much a matter of out-of-date or updated. All P1 codes are "manufacturer defined": they don't have to mean the same thing across brands, or even different car models from the same manufacturer.



If you go looking for P1121 on google, or in any generic scan tool library, you're going to find references to "throttle pedal/position sensor" because that really is what P1121 means—in some completely different car. You have to make sure you are looking it up specifically in a Prius repair manual (or using a scan tool with a Prius-specific library) to find out what that code means in a Prius (namely, the coolant control valve).

The mechanic, of course, should have known that. It's part of a mechanic's job to know that.

It's important to be super careful that way whenever you are looking up a code that's in one of the "manufacturer defined" or "jointly defined" ranges. Anything you find that isn't specifically in the repair manual for your Prius can be completely wrong for your Prius.

Even for the codes in "SAE defined" ranges, it's still important to look in the repair manual. For codes in those ranges, the little fortune-cookie description at least will be the same no matter what car is showing the code. But the repair manual is still where you find out what conditions the Toyota ECU is looking for when it chooses to show you that SAE standard code.

 

And to be fair I have replaced a throttle body in a Gen2 because the electronics in it went bad. Can't remember what the error code was for that, but it is similar and engine wouldn't idle properly until I replaced the throttle body with a used one from the junk yard. And clearly that's different than throttle pedal position sensor, but this confusion is why some mechanics have refused to work on hybrid cars for more than 20 years now.

 

Which is sad, if true, because this confusion doesn't even mean they need to know anything about how hybrid cars work. It means they need to know about how OBD-II codes work. Which, really, they oughtta.

 

Yeah the best thing I found because I don't want to remember every Prius code on the planet when I Google my codes I always enter Prius code p1121 so there's no confusion about what I'm looking for the codes for and then with that a bunch of YouTube videos pop up and various and sundry explanations from all over the world for the Prius pop-up not for the Honda not for the Nova just for the Prius. The stupid POA things or what get me 088 all that nonsense. But all that's all most of no consequence now I know by what the car is doing usually what's wrong I don't even seriously need to scan the codes of course I do to look because I'm just like that I like to own cars long enough that I don't have to do a whole lot of thinking to know what's happening that's why I've been with Toyota for 47 years almost

 

If you're going to rely on google, it does help to add "Prius" to the "P1121" in the search.

But you still end up getting every post ever made by a Prius owner who googled "P1121" and posted what they found, thinking it applied to their Prius.

 

Speak to the store manger. They will definitely exchange the intermittent part, but tell them your going with an OEM part instead and that you're willing to bring in the OEM replacement part receipt to prove it. That should get you a refund. I've worked in several auto parts stores in my high school and college days, and an honest, forthright customer will always win out. You'd be surprised how many dishonest customers buy parts to test out their assumed failure and then try to return them.

Hope this helps...

PS. If you haven't already flushed out your cooling system - do so. You may have suspended partials in the coolant jamming/locking things up.

 

If you use Google regularly and its familiar with your search habits, simply enter: priuschat P1121

And then you'll get something that's well organized and looks like this:

 

Even better, you can enter site:priuschat.com P1121

You'll still get all the posts on PriusChat where somebody googled and then came and posted about a throttle/pedal position sensor.