Help! Might have bought a lemon?

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Which OBD2 code reader are you using to retrieve the above mentioned DTCs?

 

You might consider a mini-vci cable and a copy of techstream.

Here is the work up for DTC P0121 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Repair%20Manual/04pruisr/05/2054m/cip0121.pdf

Here is the work up for DTC P0122 : https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Repair%20Manual/04pruisr/05/2054m/cip0120.pdf

 

Assuming the code reader is providing accurate diagnosis, there's a big difference between replacing a pedal assembly and the malfunctioning part being located on the throttle body?

I do question whether a P0121/0122 will illuminate the RTOD tho...not sure about that one. Kind of leads back to DTC reading accuracy.

 

Buying ANY used car that is 10 years old with over 200K miles is a HUGE gamble.

Before you do anything else, check the 12 V battery.......just because.

 

at least you didn't get a lemon

 

Good catch.

Here's another case where just looking at the one-liner "fortune cookie" that pops up for a DTC really doesn't substitute for looking in the manual for what the code means. Here the fortune cookie (at least in the English translation) really could sort of appear to be about the pedal.

 

Checking the voltage on the 12v battery shouldn't take but a minute.

Have you already tackled the workups for the DTCs posted above?

Look into picking up a $15 mini-vci cable, and loading up techstream on a laptop as a next step

 

Your symptoms sounds like a failed inverter pump that overheated the car. Check the inverter pump reservoir to see if the fluid is rapidly moving when the car is ready. No movement in fluid, your pump has failed

 

^^This

 

It's sad when SFO supplies you with a copy of the Toyota troubleshooting guide for the DTCs you "may" have, yet you haven't used them? Why not at least read them?

You'll also note that there are several of us questioning the accuracy of your code readers. Why is that? Because we deal over and over and over again with people chasing their tails due to using a code reader that doesn't communicate/decipher well on the Prius, especially with regard to the hybrid codes.

 

You haven't posted any such evidence, at least that I've seen. You posted two DTCs that both clearly refer to the throttle body, not the pedal, as you see in the repair manual excerpts that SFO posted. In essence, you were misled by the one-line "fortune cookie" messages that you saw for those DTCs, which kind of look (at least in their English translations) as if they are about the pedal, but the confusion only lasts for a moment if you read the actual repair manual info.

If you do a search for "fortune cookie" on this site, you'll find you're not the first person that kind of thing has happened to.

All that said, having been bitten once by a fortune-cookie approach to diagnosis, you might not want to risk that again. Even if you study the repair manual sections from SFO and you see that the codes are about the throttle body, that is not flat-out telling you that replacing the throttle body will solve your problem. It is telling you that the ECM is getting janky signals from the throttle body. It is even telling you in what way the signals are janky. But the ECM is stuck in a box under the dash, and has no way to go find out why the signals are janky. Is it the throttle body? Is it the wiring? A connector maybe? Even (rarely, but not impossible) the ECM itself? All that is the stuff the human has to figure out.

 

Let me preface this with I know this won't be helpful.
But this dynamic makes me nervous.

When you say, Hybrid Battery Replaced, can you be more specific? Is this a rebuild? OEM? Who did the replacing? Do you have receipts or a transferable warranty?

Red flag to me, is I just get very suspicious, if someone replaced a Hybrid Battery then sells the car, in a short time frame. My logic is you wouldn't invest into replacing the Hybrid Battery IF your plan was to sell it within 7 months. You should be making that investment with the idea that you want years more operation. Or you make some type of limited investment...just to get rid of the vehicle.

So, you have to question what happened? What justified to the original owners replacing the Hybrid Battery THEN in a short turn around ( 7 months ) reaching the point of selling the vehicle?
Could it be what is happening to you right now...was happening to them?

You hope not, you hope for sincerity from the original owners and that they weren't passing an aged and troubled Prius on to you. But you'll never know now.

I hope my suspicions are unfounded. I hope the problem is cheaper, and inevitably addressable. I hope you didn't pay too much for a 200,000 mile, 11 year old Prius.

Might you have bought a lemon?
Not if the vehicle made it to 11 years old and 200,000 miles. BUT you might of bought an older Prius that is now experiencing some serious problem(s).

Best of luck, hope it isn't something REALLY expensive or really bad.

 

Techstream can be made to work within Virtualbox and other virtualizers on your Mac.

The scanners you used are still safe to trust in a limited fashion: if they report a P0xxx code, chances are it's the real deal. However, instead of accepting the scanner's verbose text interpretation of the code, the better move would have been to skip straight to Toyota's documentation for a more precise interpretation.

In any case, the fundamental point of the Onboard Diagnostics system (OBDII) was never to tell the technician which part to change, but rather to tell the technician which subsystem needed to be examined or tested according to the service manual.

Also of note- a Prius has several additional ECUs on board, and most generic scanners only know how to talk to the main engine ECU. Sometimes you'll get something like "P0700" which indicates transmission fault. Only a few scanners (Techstream included) understand that this means they should interrogate the transmission ECU to get a specific sub-code to narrow down the fault.

 

Many would assume that an overpriced scanner would do everything needed, and maybe this one has. If virtualbox (and installing windblows) is too much, then look into picking up a used laptop ($50 or less) at one of the second hand shops (make sure it has a USB connector).

Many here don't believe in throwing unneeded parts at a problem, it becomes expensive and a time suck. Not to say that many don't do it (myself, and even the dealers), but we can all do better or at least think the dealer could

Best to follow the actual workup in the manual and go from there, if the flowchart leads you to NG (no good), then replace or fix.

Find a multimeter and probe away (harbor freight often has a cheap one for free with coupon)

Never too late to learn.