Traction, brake, and ABS lights on

That came up for me too while driving on the dry, sunny road.
I turned it off and than on again and nothing, checked with OBDII and no fault codes.

 

and check the 12v health.

 

+1 12v

 

I had same problem.
There are couple things to check. All of these you can find here on forum how to do, just search.

1. 12V battery. I replaced mine with yellow Optima battery.
2. Check if converter pump is working. You should see turbulence in the inverter reservoir once car is on and in READY state. Also, touch each hose to reservoir to feel flow.
3. ABS speed sensors on each wheel.

If you have toyota code reader read codes, if not go to dealer and have them scan it for 109 CAD plus tax.

Lights by CrniMilorad posted Jan 20, 2016 at 9:17 PM

 

Did you get "CHECK HYBRID SYSTEM" warning as well? I've been sporadically getting that, plus the warning lights circled in the above post (#5). Also, the brakes feel strange when this happens, according to the dealership the system is reverting to a fail-safe mode. It's an ongoing investigation in my case; had several diagnostic visits to the dealership, without anything conclusive. Last contact was on the phone to the service manager, who suspects it's purely a communication problem, some sorta missed "handshake".

 

Last car u had was a 1996 VW Passat that would turn off when you entered the left turn. Abs would also light up.
Story short, it was a bad wheel bearing that allowed the wheel to have some play which in turn made abs sensor not work properly and that resulted in problems.
Idk how that works on prius but after replacing the bearing all was well.

Point is that the Passat had only a few sensors while the Prius even has the ride height sensors on each wheel if you have a pcs. Any of those sensors could make problems in some weird circumstances. I would consider it a bug if it doesn't happen often

 

In my case there were no light for HYBRID.
Braking was rough as there were no regenerative braking, just mechanical, but it felt pretty rough and awkward. Dealer listed these codes
u0073 and u0293, c0215 and c1239.
After replacing real wheel hub with sensor and sensor cable, i reset codes and no problems for a month.

 

I dont mean to jack this thread, but there no need to have two post of the same thing....I have the same problem going on in my 2010 prius. But I have 2 12v xs power batteries, with a charging voltage of 14.3v and resting at 12.4v. So I know that's not an issue. But my wheel bearing are DEAD I mean there are so loud I can barely hold a conversation on the phone. Toyota wants to charge $1000 to change 2 of them..

But my question is are the wheel hub assembly and abs sensor together??

 

Copy-and-paste from my notes of our first instance:

* Took it into OpenRoad Toyota Pomo: They recorded and clear codes and test drove, say appears ok now. They say something about "computer loosing contact with brakes" is one of the codes. They advise to just drive, keep an eye on it.
* Codes: U0129, C2121, C2122, C2123, C2124, 00073, U0293
* Looking on internet:

C2121 thru C2124 mean loss of signal from the TPMS sensors.
U0129 is Lost Communication With Brake System Control Module
U0293 LOST COMMUNICATION WITH HV ECU

 

someone else mentioned road debris hitting the oxygen sensor connections, which are underneath.

 

doesn't sound right.

 

Rear wheel bearing and sensor are integrated into hub assembly and i had to replace whole thing.
Front sensors are removable. They are positioned on the rear side of the front wheel hub. Follow the cable and there is a 10mm bolt holding sensor. I took mine one out when checking and cleaned them and put them back.
I saved 350CAD replacing hub which took me couple hours. Easiest money I made-saved this year.
Replacing bearing was easy for me. I posted this tread.
Solved, rear wheel bearing removal, easy way | PriusChat

20160115_193304 by CrniMilorad posted Jan 20, 2016 at 9:36 PM

 

Yeah, cleaning was what worked on the Passat too. It's just that the sensor was unremovable without breaking so I had to pay $20 for a new sensor.

 

Hey everyone, similar issue, all the lights plus the check hybrid battery light came on. I took it to the delership a few days ago they said there was a u0129 code, they said if it comes back to bring it back in for more diagnostic. Unfortunately I am on a road trip and can't really bring it in any help would be nice

 

That U0129 is not a very common code. It means something has lost the ability to communicate with the brake ECU.

It might not be hard or expensive to fix, depending on what the communication failure turns out to be, but it seems pretty likely that something won't be working right meanwhile.

As with many of the Uxxxx communication codes, it matters which ECU in the car reported the U0129. The power management control ECU, the combination meter, the steering ECU, and the parking assist ECU if you have that, all communicate with the brake ECU, so any of those could be the one saying "U0129 hey I can't communicate with it."

A good scan tool like Techstream will show the codes grouped by whatever ECU in the car reported them. Some other tools just show you a bunch of codes they retrieved but not which ECUs they were retrieved from.

 

I had these same 3 lights come on in my car intermittently, causing loss of regen braking. The first few times I turned off the car then back on and it went away for a while. Then it came on all the time.

I think I solved mine without spending any money. What I did was after reading this thread I checked all my wheel speed sensors. For the fronts, I unscrewed the sensors from the hub, cleaned it with a rag and put them back in. They weren't dirty, just a bit dusty. For the rears, I didn't have the right pliers to take the electrical connector off from the hubs' speed sensors so I just wiggled the connection a bunch of times because I could sense some play in there, and pushed them back in as far as I could. I think the problem was dirt, freezing water and grime got inside the connector in this freezing weather messed up the proper electrical contact inside of there.

This seems to have made the lights go away. I've driven it for about 5 hours without the lights after this. If these lights happen to you, you should try this first. Just try to clean your speed sensors and wiggle them back in tight to ensure a proper connection.