Brake light turns on when making sharp turn

Maintenance/Repairs
1

2012 Ford Escape hybrid with 130k miles runs fine on highways but in local driving the brake light turns on while making sharp turn. It happens about twice a month. Light goes off when restart the car. Have this issue for a year. Everything looks normal. Can’t locate the issue. What my cause it?

2

Do you mean the brake warning light is turning on when doing a sharp turn?If so,there is a problem with the brake fluid level sensor located on the side of the reservoir or the brake fluid is low. How does the brakes feel when this light comes on? Normal,goes to the floor etc.

3 Likes
3

Agree with @COROLLAGUY1

I would add something here. IF the brake fluid reservoir is low, and turning sloshes the fluid to the side enough to flash the light on the dash. Then one of 2 things may be happening. 1) Your brakes are worn out so the reservoir shows marginally low. Just adding fluid will turn off the light but you may need new brake pads. And 2) You have a brake fluid leak and THAT should be found and fixed right away.

Seems like with either 1) or 2) you need to have your brakes checked right away - which is what that red light on the dash is trying to tell you.

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4

break fluid is full. The car brakes very well. Just the brake light turns on when making sharp turns. It happens twice a month or 20 times a year. Restart the engine the light goes a away. Scanned with IDS software but found nothing.

5

Bad brake (not break) fluid sensor seems likely

2 Likes
6

Yep. I had this exact problem in my '07 Dodge Ram. I had to replace the entire reservoir but it was still something like $18 plus the cost of brake fluid. The bad sensor also tripped the ABS light.

7

Just curious as to how a failed brake fluid level sensor would show up only on sharp turns, if (as OP says) the reservoir is full.

If the sensor is a float switch, it would, indeed, be affected on turns IF the fluid were sloshing in the reservoir, lowering the level by the sensor.

If the sensor is some kind of pressure switch (a little hard to believe), then it might be affected even with the reservoir full, with centrifugal force lowering the pressure next to the sensor. (presuming the sensor is mounted on the side of the reservoir)

So, people, what mechanism does the sensor use? Or, how would it’s failure show up only on turns, with a full reservoir?

BTW, it seems to me that either conjectured mode would be sensitive only to turns in the direction away from the sensor. OP – did you get the failure in both right and left turns, or only one direction?

(Part of my career was in failure analysis. I got paid money to ponder these kinds of problems and figure out answers.)

8

Those are usually a float operated device, mechanically connected with a lever that will actuate a switch. The float floats on the surface of the brake fluid. Acceleration forces during turning could act directly on the float, or on the fluid then the float & switch, and slightly toggle the switch. If the switch was defective this symptom could occur. Sort of like when you have a defective, worn lamp switch (for a table lamp inside the home say) that just barely works; you have to twist on it just the right amount, and no more, for it to turn the light on and leave it on. Another possibility is the float isn’t floating so good.