Got these codes. They came up the other day. But went away. Fast beeping from car as well. Regen went away and then power brakes. Not sure how to proceed.
Brake booster fail, a very common failure on gen3. Usually about $2500 at a dealer, less than half if you can diy although it is an involved set of parts and requires a Techstream bleed after. Coverage by Toyota is 10 years or 150,000 miles from first use. Don't clear the codes if you try for a policy exception with Toyota.
Yeah, they gave me an exception on the Inverter extended warranty. 3700 dollar repair. I can only hope. Prob drop it off Monday and hope for the best. Worst case, I have to pay a diag fee.
The C1252, 53 and 56 codes are all brake booster on a Prius, not speed sensor. A speed sensor code won't cause Those are serious and dangerous brake booster fail results.
is there a guide available here? Seeing how much this fails in the search results I couldn't find one. But I did find some helpful information on one post that said, if I buy the parts from a Toyota website that offers discounts and I supply my VIN I wouldn't need reprogramming? With there being 3 failure codes, I'm assuming, that there's only 3 main parts to replace. Outside of gaskets and possible O-Rings. Would you be able to tell me the names of those parts that need to be swapped out? Thanks again!
You have three codes that are very closely related, and one code that's just another problem (the left front speed sensor). The speed sensor can be dealt with some day when the more pressing business is behind you. The pump motor runs when the accumulator pressure starts to get low. Normally when the pump runs the pressure goes up as expected and the pump then shuts off until needed again. If the pressure gets low and the ECU tries to turn on the pump and the pressure doesn't go back up as it should, or even keeps going down, the ECU will keep the pump turned on for longer. If that run time gets long enough, the ECU will set C1252 ("hey, I never expect to have to run the pump this long"). If the pressure gets low enough, the ECU will set C1256 ("hey, I never expect the accumulator pressure to get this low"). As you can see, the two codes are really just telling you two different observations that might help you solve the problem. You can't really fit it into some rigid picture like "3 codes means 3 parts to replace." The two different observations conveyed by the two different codes can clearly come from the same story. Either the pump isn't pumping effectively (so the ECU can try to run it, but the pressure just doesn't go up), or there is enough of an internal leak in the system that even the pump running at its best can't keep up, and the pressure just keeps going down. Now, this C1253 code you also have doesn't want to be ignored. It's an observation about the pump motor relays (which are buried inside the brake actuator/ECU where you can't get at them). Relays allow a small, weak signal (like from the ECU) to switch a higher-power circuit (like the pump) on and off. There are mumble* of these relays and the ECU monitors them. When it sends its small, weak signal to turn a relay on or off, it also watches the relay's output to see if that happened. Surprises there will lead to this code. Now, if there's a problem with power to the pump being switched by the relays, then the story could be that when the ECU wants the pump to run, that doesn't even really happen, and so the ECU thinks it's been running the pump abnormally long but, lo and behold, the pressure isn't going up. So it would be easy for all three of these codes to be part of just one story. One way to start working out what kind of story it is would be to listen: at the times the ECU wants the pump to be running, are you hearing the pump run? If you are, then the story might be about mechanical wear or leakage. If you're not, the story might be about power not getting to the pump. With a suitable scan tool, you can get "INF" subcodes for the C1253. There are nine possibilities that will give you even more detail about exactly what electrical weirdness was noticed. Because the ECU and actuator are combined as an assembly and the relays aren't accessible, there's a chance that all these details boil down to "replace the assembly" no matter what. But still, there are ten pages of troubleshooting steps in the repair manual for C1253 and if it were my car I would follow them before shelling out for an expensive part. Not all the troubleshooting steps in those ten pages end up at "replace actuator" or "replace pump": some do, but some end at "repair that wire or connector" and that's where yours end up it could save plenty of trouble and expense. Toyota Service Information and Where To Find It | PriusChat * I was going to say two, but the C1253 INF codes tell me there are three relays. There are only two outputs from the ECU to the pump motor, and the diagram there doesn't show me what's going on internally with three relays, but they've apparently done something there more clever than I expected.
You should go to an online Toyota dealer and enter your car and or vin and search for Brake Master Cylinder*. They are different based on year, hatchback vs v wagon and tire size 15 or 17". Examples based on 2010 without specifics: Notice there are at least two. You have to email them or perhaps enter your vin to determine the exact unit. Then shop various dealers for the best new price. The brake booster pumps on 2010s can be bad as well. Decide if you will replace just the Master Cylinder Assembly or also the Pump. Make sure you find good instructions for doing the job along with Techstream or compatible bleeding and calibrating procedures. Toyota Parts Deal Genuine OEM Toyota Parts and Accessories Online - Toyota Parts Deal Hoover Toyota Genuine Toyota Parts and Accessories: Official Online Store Hoover Toyota *Brake Master Cylinder is the same as Brake Cylinder, Brake Booster Assembly or Brake Actuator. Some add names of parts in it like Skid Ecu.
