2010 Prius Brake, ABS, Traction Control Lights On

Hey guys, I had the exact same problem and feeling. As Chap said, at the beginning they replaced the brake actuator, which did not fix it, then they replaced the Master Cylinder which DID fix it! Thanks to Sean and Roger over at HybridPit over in Buena Park CA, they helped fix and diagnose the problem!, along with a lot of elbow grease, I can't thank them enough for a good fix.

Unfortunately, I am not sure how to determine which one. :/ Let me see if I can get which codes came up for them, they used a TechStream.

 

Umm, this is the gen 3 forum, did you have a different gen? I ask because in gen 3 the actuator and master cylinder are the same assembly. Or is it possible the accumulator was the part they swapped first?

-Chap

 

Won't torque pro android app with prius PIDs read all the codes??

 

Well, it's been a drizzly gloomy all day long. Earlier today, the traction control light came on on my way back to work from lunch. I figured I might've run over a puddle and somehow it got activated, but it'll be off by the time I have to go back home. Well, driving back home it was still drizzling and the light was still on. It felt like it had no power brakes. Plus, MPGs dropped down in the highway to about 38 mpg. I drive for an hour on the highway and the light never went off. I got home and pumped the brakes several times. I turned off and on the car. The light was off. I test drove it around the block. The light never never came back. Does anyone have any idea what happened? Driving all the way home in rainy weather with crappy brakes was not good. I hope this isn't a common thing with these cars.

Posted via the PriusChat mobile app.

 

Well, the problem came back today.

Posted via the PriusChat mobile app.

 

Sounds like they're in return-to-basics, fail-safe mode. Do you have anything constantly connected to OBD port?

I had an issue, apparently due to constantly connected ScanGuage, the brakes would behave like that, and lots of warning lights. Last time dealership checked they noted their Techstream connection was intermittent, if they wiggled the connector to OBD port, and suggested I try disconnecting SG.

I did that over 3 years back, no further brake problems.

 

I actually do have an obd scanner connected. I'll disconnect it.

Posted via the PriusChat mobile app.

 

I'm not sure how to scan the code for that. I'm using the Torque app. I usually use it when the CEL comes on or to check battery, RPMs, etc. The CEL hasn't appeared.

Posted via the PriusChat mobile app.

 

I have this lights on and the i hear whoosing sound everytime i press brake.

 

there's an extended warranty to 150k miles on this problem

 

I am at 282k so out of warranty
@Ragingfit @Mendel Leisk
But i got the codes pulled. There are 2 abs codes and i cant erase them. I get an error everytime i try to erase i get command rejected message.

 

Ouch!!!
Someone here has to know more about ABS than I do.

 

You're scanner may not be able to rase the codes, only read them.
You can try disconnecting the 12V battery for a minute or two and see if it clears the codes.
You can also disconnect and reconnect the plug to the abs module. I am not sure if there is a separate
one for the skid control.
But it sounds like there is a problem with the module.

 

Not sure I would stake my diagnosis on that scan tool.

If you don't have access to a laptop with Techstream, you can also get the skid ECU to flash its codes to you on the dash lights. That takes questions about the scan tool out of the picture.

 

I ordered the mini vci and it comes with tech stream. Just waiting for it to arrive.

What is the procedure to make it flash?

 

The scanner says to do the test engine off. Maybe try it with the Prius in IG-ON only (no Ready light).

 

Yes i did that multiple time. Only pressed power button twice without pressing brakes.

 

I agree with hotelprisoner, a prius will not scan or erase codes with the "engine / ignition" off. I don't know how you got the codes if your car was off. When the scanner says "turn your car off", ignore that.