Brake light and ABS light just came on! Please advise!

Is the brake fluid low?

 

Roger

 

Hows your aux battery doing?

 

Make the Prius READY, open the hood, and look at the inverter coolant reservoir. Do you see fluid turbulence? If not, the inverter pump is not working (or there may be air in the coolant loop which is preventing fluid circulation.)

 

You are kidding...right?? You seriously don't think they did an "involved" inspection. My high school buddy works at a dealer. You would be amazed at all the crooked stuff that goes on. I get an inside scoop.

 

To the contrary, if your problem started immediately after the inverter pump was replaced, that would be a prime suspect. It is not impossible that the part is bad or that it was incorrectly installed.

If the inverter pump is not working, the inverter will overheat. When the inverter overheats, the DC/DC converter that provides power to the 12V bus will shut down.

When the DC/DC converter shuts down, the 12V bus depends upon power from the 12V battery, whose voltage will sag down pretty quickly. Once the 12V bus voltage drops down, the skid control ECU will log DTC because the braking system is dependent upon proper ECU functionality.

Hence, the warning lights you are seeing may be caused by this string of events.

An alternate possibility is that the skid control ECU has failed. That will result in a four-digit repair at your Toyota dealer so I hope that is not the root cause.

 

I don't think many techs are able to really test a 12V battery in a way that is relevant to the Prius, which requires a reasonably stable supply. But that may not be a problem.

You are going to the dealer, so you will pay them $$ for a scan. But you can get the DTC's from the ABS system, using the blink codes on the dash. You have to short pins 4 and 13 on the DLC3 connector below the steering wheel, and put the car in Ready mode. Do a search for "Pins 4 13 blink codes" for more info. Patrick Wong had a post with detail. If you are able to get them, list here.

 

Hello 1st post. Have a 2004 and I was coming home tonight driving off a mountain road I travel everyday in the middle of no where no guard rails... Made it to town thank god and my brake light came on as well as my (ABS!) light, I was just starting to go from a parking lot into traffic. Had no acceleration and then brakes didn't work well. Soft braking and jerky. I live in a rural town. I called Toyota they said to tow the car to them do not drive it.. 65 miles away. So of course I am freaking out... this is bad right?? just had steering work done as well the recall about 2 weeks ago...

 

Yes, since you notice driveability symptoms and impaired braking, you need to have the car towed.

 

Yeah having it towed this morning. Man this is gonna hurt 65 miles for tow $$$ unknown cost of repair $$$-$$$$
I will post what the outcome will be.... 1st issue ever with my 2004 have 128500 miles.

 

Sure sounds like the warranty work was deficient in getting the air bubbles out and not allowing proper cooling.

 

Hi all well I forgot to come back and post.... After my $300 tow Toyota had my car for 4 days and said there were no codes they reset the computer and tried to get the lights to happen again with no luck... Paid $65 for their time. Drove home no issues for 3 months.... Until this last Saturday...

I was driving the hour and half to the dealership to get my oil changed 133578 miles and run errands and guess what the Brake Warning light comes on, the abs light and the ((!)) light again on my way there. I have never had the deadly triangle or and buzzer or warning sounds like others have reported and no VSC warning light either. Luckily I was past the curvy gotta break every 2 miles part of my trip and had been told by Toyota that I could drive it but to be very careful because my brakes wouldn't work normally. Well that's an understatement. Every time I had to use them it was jerky, grabby and really hard to stop.

Got a loaner car and went home since they didn't have a Tech there on the weekend. Got the call we all dread they said I need to replace my Skid Control ECU $2500. I was in shock and started to ask questions based on some of the info I have read here and the guy didn't really want to hear about Prius Chat. But yet they tell me nothing but I need to give them $2500. By then I was getting upset so I said I would call them back. I know I need the DTC's to get some help here and I will call and get them if there are any. I am compiling as much info/questions in writing so I can ask them questions and not get upset. I still have the original 12v battery so I will start there. Needless to say don't have the $2500 so I may just have them do the same fix they did before( reset) and try to get the $$$$ together and drive the car less. Any input would be greatly appreciated. I will call them tomorrow to see if there were any DTC's and post if there were any. thanks all

 

Yes, there definitely are DTC and you are entitled to know what they are.

Assuming the DTC confirm the skid control ECU is the problem, one alternative might be for you to buy a used skid control ECU and have the dealer install it. If your dealer will allow this you'll need to ask for the part number of the unit so you can look on eBay.

 

Thanks Patrick. I will find out today and post this evening. Will there be a specific DTC that says the Skid Control ECU is bad? I couldn't believe that there weren't codes last time, but maybe they thought what does this gal need the codes for.... When I got my receipt I thought it might show the codes but no luck. Thanks again

 

DTC C1203 and C1300 are two examples that definitely point to the skid control ECU. In addition, there are many other DTC where the skid control ECU might be at fault.

Since you are paying for the tech's diagnostic time, you are entitled to know what the tech discovered in as much detail as you request. Pls ensure that the DTC that had been logged are recorded.