Anti skid, ABS, “Brake” ((!)) (brake warning) lights are on

I believe I have the same issue. I have a 2012 prius with over 200k miles. All the brake lights came on and the whirring electronic noise was happening all the time before the lights came on. I've read that the brake booster/master and abs pumpneed to be replaced. Does that sound right?

 

I'm dealing with this now... I had a motor sound cycling on every 15 seconds, then it went to 8 and now it's every 4 seconds. I was told it was the break actuator assembly. Parts $2k and labor $1k. Mines a 2007 with 235k miles. My mechanic suggested I look for my next car. Was debating it, then figured I'd be better off paying the $3k. Then my nephew was in my car and heard a sound coming from the engine and said it will probably be going soon. then today driving my break light, ABS, VSC and "!" came on. I called my mechanics and they said it was still ok to drive. Sounds like when this goes it's like back in the days when we didn't have power brakes. One mechanic mentioned it takes a toll on the hybrid battery when driving in that mode so may not want to do it for the long haul....

I'm going to take it to my mechanics tomorrow to see if they think it's still safe to drive... Meanwhile, I'm looking to get a new Prius, but it won't be available til the end of the month, and I was planning on a 1200 mile trip between now and then, so want to be sure this will work out ok... If not, I may have to rent a car for the trip.... Meanwhile, you may want to look into the "Brake Actuator Assembly"...

 

It's never a great idea to make predictions without knowing what exact brake system trouble codes you have. It is easy to get those codes, even if you don't have a scan tool; toward the top of this very thread you can read about how to do that by counting some light blinks.

When it goes, it's like (a) back in the days when we didn't have power brakes and (b) your rear brakes are completely out, leaving only the two in front.

Mechanics saying this takes a toll on the traction battery might be thinking (as a lot of people seem to think) that the regenerative braking is the only way the car has of charging the battery. But it isn't.

 

It really does no good to prognosticate without pulling codes. Something as simple/rudimentary as a bad wheel speed sensor will disable the ABS/VSC because the ECU can't tell how fast the wheels are turning. Even in that situation, it could be the sensor in the wheel or the harness.

 

Just for sanity, you might head to a local auto parts place and buy a flare nut of the right size and thread to fit into the ports of the old actuator (which you can take in with you, to confirm you're getting the right nut).

Then see if you can start that nut with fingers alone in the new actuator's port. Sometimes it's easier—by, surprisingly, a lot—to start a nut that is not flared onto a tube, as the tube is not complicating your angle and approach.

For now, I'll bet you find out the bare nut goes in just fine, and then you'll know you just have to work harder at finessing the nut on the tube into the same port.

Then again, if the new bare nut can't be started in the port, you'll know there's a bigger headache involved.

 

That's kind of what I'd expected. Just the slight added pressure of the steel line going through the nut can make it surprisingly finicky to get a good straight start in the threads. I am most comfortable when I do get it to start easily with my fingers, but sometimes it takes me a crazy number of tries, no matter how sure I am that I'm holding that line in there absolutely straight.

 

What does work with the scan tool? Can you view the ABS / VSC / TRAC data list? What voltages are you seeing?

 

If you scroll through the data list, are any other voltages shown? I'd be interested in any labeled IG, BS1, BS2, or the like.

 

You should have had a charger on it. That is way to low...

 

When you saw it around 12 volts, was that after you finished, or during the bleed procedure?

I did come pretty close to running out of juice during a bleed procedure once. The procedure ends with several cycles of releasing all the accumulator pressure and then pumping it back up, and by the last one of those the pump was sounding like a dying windup toy. That's kind of how it sounds around 10 volts or so. But the reading could show higher when the pump isn't running and pulling it down.

If you have power available and can hang a charger on for the duration, it's a good idea.