Triangle !, ABS, & VSC Lights come on at 75mph

1. No need to reset since they go off by themselves
2. See above
3. Look at your four tires to make sure they are all the same size. If the tire size is correct, check air pressure and make sure it is correct on all four.

 

1. Yes.
2. No problem

In addition, you should raise up the corner of the car that has the tire which registered 34 psi, and slowly rotate the tire (will need to shift gear selector to N if this is a front tire; or release the parking brake if a rear tire.) Look carefully at the tread for a nail or other foreign object. I think you will find something.

 

You are amazing Patrick. I'd be shocked if you weren't 'right-on' about a cause for the 34psi tire to be leaking air and thus the cause of the error lights at high speed. Is it the VSC detecting oddities at 75+mph?

 

Yes. The skid control ECU monitors rotation speed of each of the four tires. An underinflated tire will have a smaller circumference compared to the other three and therefore must rotate faster.

The skid control ECU interprets a substantially different tire speed that continues for an extended period as indicative of a problem (perhaps with a tire rotation sensor, for example) and turns on the warning lights so that the driver will recognize that a problem exists.

 

Yes, Pat is amazing!

 

Hi Ken,

Is it possible that one tire tread is substantially worn more than the others?
Or is it possible your Prius just doesn't want to travel faster than 75 mph for the sake of fuel economy...

 

looking in my in my Prius Brief guide booklet on page 9 it says low fuel level indicator light.
maybe not getting enough fuel at speed

 

The only way that you can diagnose this problem is to do a health check with Techstream or equivalent.


iPhone ?

 

I'm pretty sure your tone wheel was damaged during the wheel bearing replacement. I have seen this before.

Avi

 

One time my wife drove for 2 days with a tire at 22 psi. I measured it before I refilled it. The tps light was on but did not trigger any other light. And she was driving at 65 mph. This happened twice. Came home and told me I filled it up and checked for nail. No nail.
Happened again the next day. Replaced tire.

I'm with Avi. Pretty obvious the mechanic given the timing of this scenario disturbed the abs sensor.

 

My guess is the speed sensor is either unplugged, or partially unplugged on that wheel or the plug got damaged while doing the wheel bearing replacement.

 

had to post on this thread because for some reason i cant seem to figure out how to start a new thread. however i have a 2005 daily driver toyota prius that i recently had the wheel bearings replaced. since doing so when i go about 60mph my (!) light, ABS light and VSC light all come on. but they go off when the car comes to a stop and do not come back on until i reach 60mph+ again. all tires are the same with the same pressure in them. anyone have any ideas? i tried to take it to the dealer but once i stop the lights go out and theres nothing for them to see. has anyone else experienced this issue??? please help. i would like to sell this prius and upgrade to a new one however i cant sell it until i feel it is safe to drive for others. thanks for your help!! JAMES4554

 

welcome!
sounds like they messed up a speed sensor. if you got trouble lights, there should be stored codes.

 

I wonder if an auto parts store could read those codes or if I'd have to take it to Toyota.

 

Could the alignment be off after replacing wheel bearing?
I'm having same issue but I didn't replace my wheel bearing. I rented out my car and noticed my alignment is off when I got it back. Happened to the driver while going at high speeds.