ABS Brake Lights with High-Pitched Noise

The alarm buzzer tells you there isn't enough pressure stored in the brake accumulator to assist your braking, and a stiff pedal that slows the car with only the strength of your leg on the pedal is what results when that happens. Something could be wrong with the booster pump, or fluid might be escaping the accumulator in some way so pressure isn't held (it doesn't have to be leaking out of the car, it could just be leaking back to the reservoir), or fluid might not be getting to the pump. Have you checked the level in the reservoir? It could just be too low. Something could have plugged the fluid line going into the pump - just in the last week or so, we had someone who had done recent work and inadvertently kinked the hose from the reservoir to the pump, and that was the whole reason he wasn't getting boost pressure.

The brake computer info can be read by a Toyota-specific scantool, so you can easily have it read at a dealer for not much money if there's one near you. Some people buy a "Mini VCI" dongle that works with a Windows laptop and seems to come with a pirate version of Toyota's software. If neither of those is an option, you can also get the codes by using a jumper wire to connect pins TC and CG (4 and 13) at the diagnostic connector over the driver's left knee, turning the ignition on, and counting blinks of the ABS light.

The codes will help figure out what's up.

-Chap

 

Looks like brake pump is gone.

 

Chap and Alex are both correct. It sounds like the brake booster pump just went out. I just experienced that on my 2001 a month ago. The good news is you got home safely, the bad news is that this is either expensive if you take it to the stealership or takes a lot of time if you try to fix it yourself.

First step is to get a Prius aware scanner. the Mini VCI is the cheapest solution. When I scanned mine, I found a bunch of codes. C1251, C1252, C1256, and C1258 I believe. C1258 wasn't something I could relate, I believe it is a generic code.

If your car has C1256, that's pretty much confirms it's a pump because you said you had brake pressure until you got home. That means the accumulator was working. Take a look at my post and Chap's discussion here and see if you want to attempt it yourself. Good luck.

 

This happened to me a month ago, it was the "hybrid abs brake booster". Cost me around 1360$ NZD.

Apparently the part is located right by the firewall, difficult to get to.

 

1360$ NZD is almost like $1000 USD, that seems very reasonable for the repair. The part alone costs over $1600 brand new, did you use new or used part? I would still think the cost is very reasonable consider you have to remove the AC lines.

 

Used, came with a 6mth warranty.

Was advised by the mechanic that new part not worth it considering the price of the car (4400$ NZD).

 

Made sense. It's a reasonable cost consider the amount of labor required.

 

Ask the mechanic if he has a 4400$ NZD that gets the same mileage?

With a new car, you pay the predictable note and have a warranty. With a used car, you pay the random repair costs. So I'm keeping our 2003 'until the wheels fall off.'

Bob Wilson

 

Excellent point!

 

Darn - I've already replaced two wheel bearings on mine. Should I have done that? Keep that up and the wheels might never fall off! Then what'll I do?

-Chap

 

The hole is on the right side of the wheel between the break and gas pedals.