Red triangle, limp mode, P2122, P2138, B2271, C1378

Now this has something to do with your throttle position sensors gas pedal position sensor that sort of thing You need to look those up someone here can give you the work up for those usually it's corroded wires and things like that a plug that's been knocked loose etc there are a couple of sensors that can be involved here someone will post the manual workup probably from the factory at some point.

 

The car has both a throttle position sensor (on the throttle, out under the hood) and a pedal position sensor (on the go pedal, under your foot), and those two are two totally separate parts, connected to different ECUs, with different trouble codes.

The P2122 and P2138 codes are both about the pedal position sensor, under your foot. More at this post.

The car definitely goes into a limp mode when it mistrusts the input from the go pedal. The other way lie lawsuits.

 

I would probably want to do some troubleshooting first. The codes from the ECU are complaining about the voltages reaching the ECU from the pedal sensor. The troubleshooting steps in the manual surely include simple checks on the wiring before concluding the sensor is bad. If you have a scan tool that can show live data, you can watch the VPA1 and VPA2 readings while moving the pedal, and maybe see what the complaint is really about. The post that I linked to above includes a graph of how the two signals are intended to relate to each other.

(It's possible the ECU live data will show the two signals already translated from voltages to pedal %, in which case you wouldn't be looking for that graph relationship, but just for them to be close to equal.)

If your scan tool can retrieve freeze frames for the P2122 and P2138 codes, you can see what the two readings were at the time the code was set, which ought to give a pretty clear idea what the complaint is about.

None. Maybe it'll be interesting to find out.

 

Techstream does all the things.

 

Huh, so they preserve the voltage offset between the two signals as a % offset after converting to %. I wouldn't have guessed that, but I guess I've never had reason to look at mine closely enough to know one way or the other.

 

Well, it's right there in your HV control ECU freeze frames. (You don't need the C1310 freeze frames from the brake ECU; C1310 is just the brake ECU saying "hey, HV control ECU says something's weird over there, go get those trouble codes", which you've got; it doesn't otherwise matter what the brake ECU was doing at the time.)

Remember that when Toyota had to align their "Accel Pedal Pos #1" (VPA1 in the wiring diagram) and "Accel Pedal Pos #2" (VPA2) sensors with the SAE standard trouble code names ("throttle / pedal position sensor / switch" A, B, C, D, E, or F), they went with "sensor D" for accel pedal pos #1, and "sensor E" for accel pedal pos #2.

So you look at your first code, P2122 "throttle / pedal position sensor / switch D circuit low input", and you look in the freeze frame and while accel pos #2 ("E") is 57.2%, accel pos #1 ("D") is stuck at 0.0%.

You've got that one P2125 (a complaint about E circuit), because that time #1/D was not stuck at 0, but was reading 23.5%, but still #2/E was way more (50.1%) so the ECU decided to mistrust the E input that time.

But all the rest of your codes are about #1/D or about D vs. E miscorrelation, and they're all showing #1 as stuck at 0.0% (usually) or, like, 1.5%, while #2 is reading whatever it reads.

So it looks like you've got some (maybe heat-related) fault where the VPA1 input goes to zero (or close to zero) intermittently. I can't say for sure yet if that's the Hall effect chip inside the go pedal, or the VPA1 input circuit of the ECM, or some wiring connection in between. Or the supply of power to the Hall chip (comes from ECM pin VCP1 and returns to ECM pin EP1) might be dropping out, which would be an ECM problem. Might be able to take the pedal out and test it on a bench, maybe with a hair dryer to warm it up. If it misbehaves on the bench, you've got your culprit. If it behaves, maybe there's a wiring or ECM problem, and more tests you could try.

Those are pretty much the troubleshooting steps you see in the P2122 section in the repair manual.

 

The HV control ECU doesn't have an engine coolant temperature sensor wired to it; it just has to ask the ECM for that info. I'm guessing it just hadn't asked yet.

32 ℉ looks like a weird choice for a not-yet-initialized value, but of course in Celsius which the ECUs use, it's just zero.

 

It is, but it's not really prone to the sort of "moving part" problems you might be thinking of.

In gen 1 it was, because the two sensors were nothing but mechanical potentiometers that could wear out and get dirty.

In your generation, all that moves is a piece with magnets on it, and nothing touches the Hall-effect ICs that detect the magnetic field and make the electrical signal. So if one of them has failed, it's just failed the same way other electronics fail, and not because anything moved.

So that might be less of an argument for it being more likely than a similar failure anywhere else.