Hello - the Brake Light, ABS Light & Traction Control Light are on, I searched the forums and internet but I'm not finding a solution. I have no codes being thrown on OBD. The car has been making a weird intermittent hiss noise when stopped and the brake pedal is pushed in (stop lights, queues...). Braking has been diminished - pedal goes down further than it did before and feels squishy. No signs of exterior leakage. I was thinking master cylinder leaking internally but I see posts discussing a brake actuator. Has anyone had the Brake Light, ABS Light & Traction Control Lights without OBD codes? Thanks! Rich
You don't need Techstream for brake codes; the car is built so you can read those any time you need to by using a short wire between the Tc and CG terminals on the diagnostic port, and counting blinks of the dash lights. Searching by those terms will find you posts with the rest of the details. Techstream or another working scan tool may be easier, sure, compared to counting light blinks. But when an issue is reported from the braking system, it is good to be able to have the codes right away, whether or not you have a scan tool nearby, or to work around a scan tool that tells you there aren't codes.
Thanks for the replies everyone!! 1st time using the Techstream. After getting it to work and through the learning curve pulled codes C1391 (Abnormal Leak in Accumulator), C1464 (Front Speed Sensor RH Circuit) and C1465 (Front Speed Sensor LH Circuit). Does this sound like the Brake Booster Pump Assembly(Accumulator) more so than the Master Cylinder? Thanks again! Rich
That is hard to say from a distance, even though the fortune cookie has "accumulator" in it. The lower unit (pump/accumulator) is responsible for pumping up the pressure, but where the pressure is leaking off could be in either unit. The upper one (master cylinder/booster/actuator) has the lion's share of all the valves in the system, so it will often be the culprit. If it is leaking off quickly, you can probably tell which unit is hissing, with a simple mechanics' stethoscope. How many miles on your 2012? If you are under 150,000 and within ten years of first use, you are covered under Customer Support Program 20TE07. Don't clear any codes, and get thee to a dealer.
Thank you! The Prius has 302K. I might start with the Brake Booster Pump since the Techstream code indicated "Abnormal Leak in Accumulator". Have you done this? and if so, any "gotchas" I need to look out for? Rich
As I mentioned, even though the fortune cookie for the code says "in accumulator", that is not always where the leak is, and in fact it more often turns out to be in the upper assembly (master cylinder/booster) because that's where the lion's share of the valves are. If you want to be more sure, you can touch each unit with the tip of a mechanics' stethoscope to find out in which one you hear the hissing of the leak. If you just want to jump into replacing one or the other unit first to see if that does the trick, you can start with either one. Neither one is much of a fun job. The pump/accumulator is particularly cramped for access; you might want to see if you can find a copy of the technical instructions for the T-CP-D0H-A510-D recall, which shows some special tools Toyota dreamed up to make the job easier, when they were facing a chore of replacing 89,000 of them.
Ouch! they are both kinda pricey. Maybe I will invest in a mechanics' stethoscope... Thank you so much once again for your advice. Rich
Same issue on my car (Abs and TC lights on) I jumped the pins on mine yesterday, and now the red “Brake” light is on. What did I do?
What numbered sockets / pins in the ODB2 connector did you jump? The numbers are usually printed above on the upper row and below on the bottom row to the sockets. You'll need a flashlight to see them. It's easy to flip the socket numbers while looking at the ODB2 connector upside down when jumping the two sockets.
Did you get this resolved?... mine is throwing the same errors (plus U0146 and B2060) and was thinking I'd do a brake flush.
