Brake Light coming on under hard acceleration

[Mjkkb2]

Ok, so this happened to me on several occasions. During hard acceleration with RPMs in 4k or above the dash brake light will come on for a split second or 1s. It does not happen every time just sporadically. Anyone have any ideas? Is something bad to come?

thanks much!

[Frog]

Just for fun check the brake fluid level. It could be low.

[Mjkkb2]

Will check, thank you

[mexillis]

are you peeling out or is this hwy acceleration? My initial though is the VDC kicking on but still weird your brake light is flashing momentarily.

[Mjkkb2]

Not highway, more from a stand still going from 2nd to third and usually with the wheel turned a bit. Doesn't happen going straight.

[Mjkkb2]

brake fluid checked out fine. I am starting to wonder if this is an indicator that my pads are wearing down to nothing. Thoughts?

Also, the other day I floored it and the light stayed up for like 2.5 seconds.

[Debonair]

I don't recall seeing any sensors for brake pad wear on my 11' M, but I don't have the "S" trim.

It could be an ABS wheel speed sensor issue or even an issue with the parking brake sensor. You might have to get a scanner and check for codes from the ABS system. A higher end scan tool will also allow you to record the ABS data while the car is being driven. Then once the issue occurs the data can be reviewed and scrutinized to find the cause of the issue.

This could even be an alternator issue since the car is always under load when it happens, but this is less likely since (presumably) no other warning lights are coming on at the same time.

[Mjkkb2]

I was also thinking parking brake, since it's the same light that comes on when you apply it. I'll try scanning for codes over the weekend.
Thanks!
Just to clarify - the dash light I refer to is the red "BRAKE" one, not the round symbol with an exclamation point.

[beav626]

im getting the same thing, So i'm following this and will scan my car too

[M56STL1]

My M56 does the same thing.

[Mjkkb2]

No codes for me

[beav626]

added some brake fluid and Im good. my reservoir wasn't very low but it must be sensitive.

[Mjkkb2]

thanks for the tip. I have topped off mine also, (was between min and max mark) and the light didn't come back in the last week. Wonder why is it so sensitive and what does actually happens to the fluid level while accelerating hard.

[Altered]

The brake fluid level sensor reads in the center of the reservoir not the rear, so under hard acceleration the fluid flows to the back of the reservoir rapidly and leaves the sensor exposed. When the level is at "MAX", it will cover the sensor at all times. I would still take a look at the brake pads, the low fluid level usually indicates its time for new pads and possibly rotors.