So I bought a used 2013 prius (dont know what trim level) with about 156k miles on it. The traction control and ABS(!) lights were on, but for the price I couldn't pass it up. I went to the dealer to see if any DTC's popped up, and sure enough the only code on there was C1247 (stroke sensor). From what I can see on other threads here, possible issues include the stroke sensor itself, the wiring harness, and the skid ECU. Another issue I noticed later was that the regen brakes wouldn't work, or so I thought. When on cruise control, if I hold the CC lever down, the car uses the regen brakes to slow down. So, for some reason the regen system doesn't want to work with the physical brake pedal. However, cruise control will shut off by depressing the brake pedal by even the slightest amount. At first I thought it would just be the stroke sensor, but now I'm not sure. And I don't trust the dealer to not recommend the most expensive fix first. If it does end up being something expensive then so be it, but I figured I'd give it a shot here first. Any help will be much appreciated!
Don't be afraid of the dealer. Worse case they charge a hour diagnostic charge. In your case you may qualify for a free repair on a Toyota extended warranty for the brake actuator.
They quoted me 160 dollars just for diagnostics, I dont know if I want to do that for the off chance that a warranty will cover it. I ordered a mini vci and will attempt to find the issue, but I'm still open to trying it with the dealer if it comes to that.
Its more than an off chance. Most hatchback gen3s are eligible for it except the 2010s whose extended brake actuator expired in Dec. The Prius v wagons (this forum) are not covered. The brake actuator has an integrated ecu, is part of the regen logic and is dangerous if it fails completely. You can find an independent Prius mechanic if you want to save on the diagnostic, which should be free at the dealer if the brake actuator is the issue. One accident and you will wish you fixed it right away.
Just got this in a email..... Toyota Brake Booster Pump Class Action Lawsuit Filed | CarComplaints.com
I had these lights come on intermittently. I wiggled and tightened the rear wheel speed sensor connectors and cleaned the front speed sensors and put them back in. That seems to have fixed the problem.
How long has it been? Did you clear any codes? Better consider yourself lucky..... usually that's the traction battery or inverter
Possibly. It just came on in the last few weeks when I left the car out in freezing conditions more than usual. Been prob free for the last 10 start/stops or so, totaling about 5 hours of driving time. Some water and grime may have seeped in between contacts in the sensors, and when it froze, may have disturbed the electrical signals. No CEL. My torque app showed no codes. Disagree about the traction batt or inverter. Worst case it could be the brake actuator which can be just as costly
It is easy to get the trouble codes when these three lights come on, which is how you find out why the brake ECU has put those three lights on. It's approximately useless to base anything on just "had the same 3 lights" because those are the only 3 lights the brake ECU has to alert you to problems with, and it uses them for pretty much all one or two hundred reportable issues. If you don't have a scan tool, you can still get the trouble codes using nothing more than a short piece of wire, and counting the blinks of the lights. There are a lot of posts here on PriusChat on how to do that. If you retrieve the trouble codes and the ones you get are about wheel speed sensors, then that would give you a good reason to at those sensors, as robomoto has done here. If you retrieve the codes and the ones you get are about something else, then you would probably skip fiddling with the wheel sensors so you could spend your time checking out whatever issue is really being reported.
An example of "first-world problems" is "do I go back and edit the posts now that I see I left a word out?"
I'm just about OCD enough to do that. Drives me nuts that we have a time limit on editing our own posts.
Yup! Been there. Brine solution worked its way into the sensor connector. Disconnected, cleaned, lubed, reconnected, and resolved.
That will be especially likely to be worthwhile if the trouble code that is being reported is one to do with a wheel sensor ... which will also, often, save you time by hinting which one to look at.