Prius Red Triangle light on and other lights, now car won't go into drive or reverse

There are more than one thing that can cause this, but a common one is a p0AA6 code.
See this:
If you need to get the car working again, you can probably reset everything by disconnecting the 12v battery. Just keep in mind this will make the codes disappear, no longer available for reading, unless they come back.

Exclamation Point, Hybrid System Warning Light, All other lights car won't start | PriusChat

 

The traction battery is one of the places where the cause of a P0AA6 code can be. Other places include the frame wire, inverter, transaxle, or air conditioner. With a scan tool that can read INF codes, you can get it narrowed down to one of those general areas, making the search easier. (All still assuming, at this point, P0AA6 is what you've got, since that hasn't been confirmed yet.) If you don't have such a scan tool, you can read about some other methods for narrowing down the location of the fault.

That's a code where, even if the fault does end up being in the traction battery, it can turn out to be a repairable fault. It doesn't inevitably mean the battery is toast.

 

Getting the trouble codes should be the first order of business. Most repair shops should be able to do that, but whatever codes they give you, you might want to post here so we can make sure they got all of them. (Some places have scan tools that won't retrieve all trouble codes in a Prius. Often we can tell, because they will retrieve some code X that means you also have some other codes Y or Z, and the list they give you doesn't have Y or Z, we know they didn't get all the codes.)

If TMR-JWAP is right and there is a P0AA6 code, you might want to look for a shop with a specialty in hybrids. That's a code for insulation failing in the high-voltage system, and none of it is rocket science, but many non-specialist shops will say "high-voltage system, ai yi yi, not us!".

If you are DIY or DIY-curious, we've got resources here for narrowing down some of the possibilities on your own. "High voltage" should be taken seriously, and there is some personal protective equipment that goes with that kind of work (especially if failing insulation is suspected), and it's helpful to have some electrical background, but otherwise it's not especially difficult work. Yes, some of the possibilities can require somewhat expensive replacement parts, but not all of them.

I'm still getting ahead of things, as you don't have the codes yet, and we don't know if P0AA6 is even involved.

 

There are many more things in a Prius than a 12 volt battery, an engine, and a traction battery, and many, many things that can go out of kilter and set trouble codes, and the computers in the car are programmed to take specific actions for some of those, such as refusing to shift into drive or reverse.

For some reason, people very commonly want to assume that there's just some small handful of possible problems, and they can use a thought process like "it's not this, it's not this, it did such-and-such one time when it was that, ..." but it really doesn't work that way. The available trouble codes are numbered in hundreds. Really the first step that will cover the most distance is making sure to retrieve all the trouble codes and look up what they are revealing.

 

possible

 

You were lied to by them claiming the repair would last 3-5 years. It's more like 6-18 months. There is a reason Toyota does not mess around with secondhand batteries or do "module replacement repairs" and that is they want their customer to have reliable cars.

If you want a reliable car, get a new battery installed, and then you will have a car that is reliable for the next 10 (or more) rears. Added bonus you will not need to be looking for another car in 3-4 years time.

You need to stop thinking about what you need to spend on the car for repairs versus "what the car is worth". Think about what it will cost you to replace the car for something similar and could you do that for less than the cost of your upcoming repair.

 

For a while, you should be able to just disconnect the main cable from the 12v battery to reset the car and make it drive again. At some point, the fault may become bad enough that it will lock in right away, as soon as you start the car. Some people have installed a switch between the cable and the battery so they can rest it quickly, and used it like that for many months. Not the best solution, but everyone's circumstances are different.

The odds are very very high that it's a HV battery issue. There's probably 1000 battery failures for every inverter or transaxle failure. What warranty were you provided when the battery was replaced? Was it a complete salvage yard battery or from one of the large rebuild companies like Dorman or GreenBean?

130k on a Gen2 is a youngster. If the body and interior are in good shape, this car should have a lot of life left in it. Unfortunately, one item to consider is the condition of the ABS pump. If you sit in the car while it's in ready mode (and radio off so you can hear clearly), slowly pump the brakes until you hear the brake pump turn on, then take your foot off the brake pedal. That pump should only run for a few seconds to pressurize the brake fluid accumulator. Start counting seconds from the time you release the brake pedal until you hear the pump start again.

If you count to 60 with the pump not starting again, you're in pretty good shape. In a perfect system, the pump will run only after the brakes have been pumped a few times. Sometimes the ABS system develops leakage and the pump needs to run every 10 seconds. This is when the car is rapidly heading for abs failure codes and a $2k repair.

 

First off, there is an answer waiting for you that is not just somebody's guess. That will be the second INF code stored along with the P0AA6. As soon as you bring a scan tool to the car, or the car to a scan tool, that can read the freeze frame and INF codes, you will know—not be guessing—whether the P0AA6 fault is in the battery, or the inverter, or the transaxle, or the air conditioner, or the wiring.

Then, plans for what to do about it can be made.

 

You need to cycle the car (IG-ON or READY) one more time and it will set the second code.

 

^ This.

The car posts INF code 526 as a "note to self" so that the next time it starts, it will go through a modified starting procedure and try to identify the area of the leakage, and then set a second INF code.

So you can definitely catch it at times when there is still only 526. Sometimes people have a mindset of "clear the code and see if it comes back", which of course guarantees they will keep seeing only 526.

There might be times where, even without such interference, it still somehow fails to set the more specific code on the next start. I can't guarantee that never happens, but I don't think it's common.