Dashboard Lights ON: Red and Yellow Brake, ABS and Slip + Beeping + Noise in Engine Bay

Sorry, but brakes are a safety issue.
So if anyone has a problem with them, my advice is always to have them professionally checked out.
I'd just feel really, really horrible, if I gave any other advice, and it lead to an accident or worse.

I'm pretty conservative with advice about Brakes, or Tires.
So I'm going to say, "Check the Codes, and Take it to a Dealer".
Stay Safe. Good Luck.

 

I'm not sure I can help, I was curious about the noises, but I can't open the link. Maybe post it to Youtube?

 

Good day everyone,
I’m having the same exact problem but my traction, abs,brakes light and also a yellow exclamation are all remaining on the dash.
Any advice??

 

If taking it in for reading CEL code is not an option then you can either:

Drive it without proper brakes til you cant stop and get into an accident

OR

Throw random brakes parts at it until the light goes away, which could add up to couple thousands and might not even resolve the issue

 

I was able to use the link you provided above to hear the sounds.

I have not yet experienced an ABS actuator failure, but have been concerned that it may eventually manifest itself on our Gen 2 car, since this has happened to many cars of that generation as they age. In the case of the Gen 2, I know that Toyota had issued a Technical Service Bulletin that authorized local dealers to repair failing ABS actuators and bill TMC, if the car produced a certain set of error codes that were indicative of actuator failure, but the program ended as of Dec 31, 2018.

The sound in your video that repeats at intervals of 15 to 20 seconds does sound to me as if it could be the ABS actuator trying to pressurize the system. It sounds similar to that our Gen 2 makes, but that is far less frequent, the time interval of that can be measured in minutes. The other sound in the video sounds similar to that our Coolant Heat Storage pump makes after the car has been shut down, but I believe that system does not exist on the Gen 3 car (unless it was still part of the Canadian model, not sure). If your actuator is failing (or in your case it could be the accumulator, as I believe that is a separate unit on the Gen 3), as would be indicated by the frequent attempts the actuator is making to pressurize the system, there may be a separate TSB that would apply in your case. Perhaps @Mendel Leisk or @Tideland Prius would know if such a TSB is in effect in Canada. @ChapmanF would be able to help you understand the nuances of the ABS braking system in the Prius.

In any event, I'm sure that all of them will tell you that you need the codes in order to get any help from Toyota. If you are unable to acquire a copy of Techstream, it may be worthwhile to pay the dealer's diagnostic fee, if you can get assurance from one of the Canadian members that it could be fixed for free.

 

All of them, and all of us are just assuming. Best to save your words, see post #10.

 

no obdii dongle either? wonder if dr prius or torque can read brake/abs codes, no?

 

a piece of wire can read the brake/abs codes (in abridged form).

Frequent running of the pump can reflect pressure not holding well, which could mean an internal leak somewhere, which could be either in the actuator assembly or in the accumulator assembly (as davecook89t hinted, they are distinct assemblies in Gen 3). Codes by themselves may not help you localize a leak into one or the other assembly; a mechanic's stethoscope might, or active tests in Techstream, or a combination of both.

Like a house's well water pump, frequent running of the pump can also mean some of the gas charge is lost from the pressure vessel.

But how frequently the pump runs also depends on what use you're making of the brakes; in stop-and-go traffic, hearing the pump frequently is to be expected.

 

What you think is "solid reasoning" might not be at all.
Computer controlled systems often defy simple logic.

We see evidence of time and money wasted on here almost every day........by people who think they are making an educated analysis.......when it really is just a wild guess, often based on incomplete information.

And if you mean Do It Yourself (DIY) options, there really aren't many EASY ones except for routine maintenance.

People in forums like this will usually give you an honest opinion.
They aren't always pretty.
If you can't take the heat.............

 

The pump doesn't compress air (directly); it pumps brake fluid. The brake fluid is pumped into an 'accumulator' that also contains trapped nitrogen. The nitrogen compresses, thus brake fluid stored under pressure. A good analogy is a house's well water pump and pressure tank. The accumulator has a bellows meant to keep the nitrogen on one side and the fluid on the other, so they don't mix. The nitrogen charge is intended to be 'permanent' (= as long as the bellows lasts).

Like a well pump system, any loss of gas from the pressure vessel will mean the pump runs shorter, more frequent cycles.

Gas bubbles in the hydraulics can have weird effects. In a simpler brake system, usually you could tell when gas was present, because your brake pedal feel would be mushy, and with big enough bubbles, it would be hard to stop.

The Prius system doesn't behave that simply, because it has active feedback control. The computer decides what fluid pressure it wants to send to each brake, and it has a sensor telling it the pressure at each brake. If there's a gas bubble in a line and the pressure doesn't get to the target right away, the computer will just hold the valve open longer to let more fluid into the line until the bubble is compressed to the target pressure. That happens too fast to notice. So instead of giving you a kind of progressive mushiness that lets you know there are bubbles in your lines, Prius brakes tend to go on feeling more or less the same until they don't. (That's one reason they're wrapped in so many layers of sensors and warning lights and buzzers, other ways to warn you of trouble since you can't count on how the pedal feels.)

Out of all the brake problems that get reported on PriusChat, a very rare few of them fall into the "floored-pedal-no-stoppie" category. It's good that those cases are so rare because of course they're highly undesirable.

My speculation about them is that they would result from progressive growth of gas bubbles in the lines, maybe from a slow bellows leak, producing generally no change in brake feel until finally growing large enough to trigger the ECU's safety mode where it had to let so much fluid into a line it now thinks there's a leak there and gives up.

But that's my speculation; it would take a lot more evidence gathering that I have no way of doing before it could be anything like a conclusion.