brake pedal chatter and warning light

[dirtdestroyer7]

hey everyone, newbie to the forum here. have done some searching on this site (and everywhere else) but haven't seen anyone with the exact problem ive been having yet.

so yesterday while going very slow (crawling) I stoped and with light pressure on the brake pedal it started chatering and clicking acompined by one of my dash warning lights flashing (not sure which one but it was on the right hand cluster towards the bottom). anyone else ever experience this? it a 2013 4runner with 30K miles.

thanks for reading!

 

[Boyds4Runner]

Usually that's the emergency braking function.

I have had that happen in a parking lot or two where I slammed on the brakes as a pedestrian caught me by surprise and the electronic brakes sensed an "emergency" stop and made more noise than I would be comfortable with.

Make sure it's just during sudden steps on the brakes.

Otherwise it would be an indicator that something is sized differently than the computer is used to such as well oversized tires or undersized that changes the expected wheel speed sensor settings or even a bad wheel speed sensor itself.

 

[dirtdestroyer7]

Usually that's the emergency braking function.

I have had that happen in a parking lot or two where I slammed on the brakes as a pedestrian caught me by surprise and the electronic brakes sensed an "emergency" stop and made more noise than I would be comfortable with.

Make sure it's just during sudden steps on the brakes.

Otherwise it would be an indicator that something is sized differently than the computer is used to such as well oversized tires or undersized that changes the expected wheel speed sensor settings or even a bad wheel speed sensor itself.

thanks for the reply, interesting as I don't believe I slamed the brakes but I was on some off road terrain. ill keep an eye on it but glad to hear that im not the only one that its happened to and it doesn't seem to have been a huge issue! love the runner and for the cost im hoping to get a pile of miles out of it with out to much maintenance cost!

 

[Boyds4Runner]

Actually, on further re-reading your event, it could just be a simple case of the ABS triggering after one of the tires sensed a "slip" on something as you were trying to come to a stop. Maybe grease on the road or wet leaves. Especially since you said you were going slow.

The Chatter and dash light (car symbol with skid marks) usually indicate that ABS had to actuate for whatever reason set it off. If you are not used to driving a car with ABS then it is a bit disconcerting but part of the technology where a computer takes your pressure on the brake pedal and calculates how hard and whether to pulse the brakes or not due to the relative changes in wheel speed on each wheel.

Should be normal but keep an eye on it if you don't think it's appropriate for your ratio of brake pedal pressure and road conditions.

 

[JSparky]

I agree, sounds like abs/traction control activating. Were you in 4wd?

 

[dirtdestroyer7]

Hey guys, im going to agree with the ABS. thinking back on the event, i believe there was a rock that the tire may have slid on ever so slightly when coming to the complete stop. Ive had ABS vehicles before and don't really care for the feature, but pretty standard on all these days. this one just threw me for a loop with the noise it made and the dash light flashing. loving my runner and still getting used to some of the features on these newer vehicles (brake assist, swoohing brake noise, knocking engine.... do some searching and all normal!). can get used at any noise as long as its going to run forever!