Stroke Sensor - No Brakes

I was going down the highway at 70mph and came up to a toll booth when the brake pedal went to the floor and the car wouldn't stop. I hit the pedal hard and the car stopped in a very jerky manner as if the abs was initiated. I looked at the dash and the ABS, (!), and brake lights were illuminated. I turned the car off and then on again and the lights were off and the brakes worked normally again. The Toyota dealer in CT said the weak battery was causing an under-voltage at the stroke sensor and replaced the battery. They told me if I lost my brakes again (!) I should bring it back for a new stroke sensor. In hindsight, I should have just told them to go ahead and replace the sensor. Two days later, driving down Florida route 301 in the rain, a stoplight went from yellow to red in about 3 seconds so I hit the pedal hard. The back brakes immediately locked up, the front wheels kept rolling, the car swerved and slid through the red light intersection sideways. I counter steered and slid between two cars at the other red light, on the wrong side of the road as I straightened out. The car swerved and slid sideways again in the other direction and then spun around so I finally wound up in the correct lane, and I drove off like nothing happened. I was doing maybe 35-40 at the time and it's a miracle no one got hurt. Again I look down and see the lights illuminated. I cycled the power switch as before, and again the problem went away. About an hour later the problem came back and this time no amount of power cycling will clear it. Basically what I'm understanding now is that it's the regenerative side that doesn't work with the bad sensor. The hydraulics kick in at around the last 10% of the pedal so the car will still stop, but I have to floor the pedal and that makes the car think your trying to lock up the wheels so it initiates the ABS system which makes stopping jerky and unpredictable. BEWARE the stoke sensor!!! What a dangerous design!! The dealer has the car now...

 

Florida dealer THINKS it MIGHT be the ABS actuator ($2700), Connecticut dealer THINKS it might be a stroke sensor($420). Florida dealer is emailing Toyota engineers for advise.

 

They said the code was for the stroke sensor but a lot of things can cause the code and the stroke sensor tests ok and they've seen a lot of ABS actuators failing so they assume it's that. I paid the $109 "diagnostic fee" and took the car. They wanted $2700 and I'd have to rent a car for a week. It's kind of at that point where the money I'm spending on repairs could buy a new one.

 

The code the tech found is C1247-Stroke Sensor Present. "He found the stroke sensor readings to be within calibration"

 

Honestly I only noticed the lights after the fact both times. I'm half wondering if I should just have another dealer flush the fluid out and re-bleed the lines. You would think this would be a major issue with safety recalls. So far they're basically just treating it like an old car with a bad part. Not their problem, but a quick google search shows the problem in both older and newer cars.

 

I decided to take the car to a second dealer. I asked them to drain the fluid and bleed the air out of the system. I told him that I lost a bunch of fluid when changing the rear brakes because a wheel cylinder fell out and the pedal now goes to the floor. They had the car for maybe 30 minutes and told me they didn't change and bleed, but re-calibrated the system and that everything is now fine. $48 out the door. So far so good. It's been 3 hours of driving around the Tampa area with no problems. I am definitely a bit weary. I've seen a few posts where this fixed the problem and then it came back X days later, plus I still don't know what caused it in the first place.
I agree that the redundant system likely saved my life but when the hydraulic side is all that's left, for whatever reason, only the rear brakes work. Because of that I spun out of control in the rain... I knew the car was a ticking time bomb when I bought it new and swore I'd get a new one before 10 years for this very reason. Electronics and electrical systems can be very unreliable when they're old.

 

Yes. So here I am 2 years later. Ive been driving for 2 years on basically the hydraulic system alone. I did learn however how to reset the system with a paper clip. Resets the system and restores braking to normal until the next traffic jam. Murphy's law dictates the exact moment of release but with practice it is possible to thread the needle in a panic.
A side note... I did also figure out how to bleed the brakes. A simple request that 3 different dealerships refused to do. But, If you cycle the power while someone opens the bleeder the car runs the brake fluid pump... Mine had LOTS of air in it. Car went 3,000 miles with no issues after I bled the air. After that I got lazy and keep a paper clip handy. Best to keep an eye on your rearview mirror ;-)
Also, the entire dash light speedometer cruise control has been blacking out intermittently for over a year, as mentioned in a recent consumer reports.
Believe it or not, I still love the car. I also live in it so idk maybe its Stockholm syndrome.

2005, 170,000 miles, 35mpg