Brake issue - ABS, Brake, and Parking Brake warning with tone...

I started my 2008 Prius last night after being parked for about two hours, and after about a minute (I stayed parked as I was making a call), there was this loud, high-pitched tone that wouldn't shut off. Also, the red parking brake light remained on even though I had released the parking brake (I checked several times with that tone ringing), and the yellow brake warning light, and the ABS brake warning light remained on.

I shut the car off to see if it was a glitch, and the tone remained on even after shutdown until I took my foot off the brake. When I started it up again, the tone and warning lights came back on. I tested stopping the car in the parking lot, and the brakes worked but locked up, bringing the car to skid stop. I pumped them several times, to make sure they would continue to work, then brought the car home carefully with the four-ways on. The tone and warning lights never shut off.

When I got home, I felt for heat at all four wheels and detected heat coming from only the front left brake. I also checked to see if the parking brake was working properly, and it was.

Coincidentally, I was just at the dealer the previous day for the HV water pump replacement recall, the steering shaft recall, and the accelerator reshaping recall. They did replace the HV water pump, they only replaced a bolt for the steering shaft, and they reshaped the accelerator pedal. I doubt this is relevant, but better to add info.

Can a seized calliper cause the ABS light to come on?

Many thanks,

 

Hey folks,

Thanks for the replies! I'm definitely going to look into buying a OBD2 reader. Is there a particular one that is best for a Prius?

I took the car into the dealer yesterday, and the hybrid specialist checked the callipers and found that none were seized. He figured the heat at the front right hub was being caused by that brake possibly working harder than the others. He did the diagnosis on the brake actuator, and found the resistance on all 6 testing points to be exactly where the should be. Getting to the connector terminal was a PITA. He had to take the wiper assembly off, and the metal pan that the wiper motors sit in to get anywhere near it. Then, in order to unlock the connector terminal, you have to pull a white locking slide out towards the front of the car, and then disconnect the connector pulling it to passenger side of the car. Unfortunately, pulling the locking slide out to release the connector is pretty much impossible without moving the big aluminum "hybrid system" inverter, as there is no room for the slide to be pulled out.

The repair instructions eventually led to diagnosing the problem as with the Skid Control ECU. The parts guy comes out and tells me the part costs $2,088.00!!! I felt sick.

The mechanic said there was nothing the could do until Monday, and that I'd have to wait until then, so he put the car back together since the Skid Control ECU is in the cabin near the glove box anyway. As he was putting it back together, I was asking him if it was a possible glitch, as I had a computer that once wasn't working, and when I took it in to the Apple Store, it worked fine. They figured that the computer was working again because it had been disconnected from power for a while and all the residual electricity had dissipated and the system had reset itself. Well, once the mechanic had the car back together, the high-pitched tone and all the warning lights were no longer on. He got out his laptop and checked the fault codes, and found none. We took it for a test drive, and the brakes worked fine again.

He asked me to see if the problem comes back over the weekend. I'm really hoping I don't have to shell out over $2000.

 

Hey guys,

Thanks for all the help and tips! Very much appreciated!

I'm pleased to report that the problem has never come back so far.