If your brake fluid is also running low, you probably have a help in your cruise control brake pressure sensor. The brake fluid shorts out the sensor and eventually you'll blow the fuse for the abs, AC, and spedometer/odemeter. Replace the brake pressure sensor. Its under the master cylinder resevour. Remove the air filter first and there lots of room to work. This is a relatively easy fix, the part is about $35.
Connected to the master cyclinder.
Here is a PARTIAL list...backup sensor?door ajar sensor?O2 sensors (got about 3 or 4 of them in different places.)engine temperature coolant sensor?Engine Oil temp sensor?Engine vacuum manifold pressure sensor?Engine atmospheric pressure sensor?Mass Airflow sensor? (MAF)throttle position sensor?windshield washer reservoir level sensor?Crash-velocity-sensitive-airbag deployment sensor?fuel-tank full/empty sensor? (gas gauge)oil pressure sensor?seatbelts need to be used-sensor?heating a/c temperature sensors?A/C clutch sensor?A/C system pressure sensors?Crankshaft position sensor?transmission gear selector sensor?Overdrive sensor?Locking torque converter sensor?anti-lock brake wheel sensors?anti-lock brake master cylinder sensors?brake pedal sensor?brake light-brake pedal switch sensor?windshield wiper motor sensor?fuel mixture sensor?ECM module sensors? (various)brake fluid reservoir level sensor?
I have the same problem - I was recommended a brake fluid drain and brake fluid sensor replacement - haven't done it yet, but hopefully it works. Dealer quoted me $190.
Mounted somewhere on the brake pedal lever, or possibly a pressure switch on the master cylinder, depending on the vehicle.
There is no brake light sensor. There is however a brake light switch. It may be mechanical, which would be located somewhere on the brake pedal lever. It can be bad or just out of adjustment. It can also be a pressure switch located on the master cylinder.
cruise control switch
It will be a oil pressure sensor
Brake sensor indicator
The brake pad wear sensor is on the brake pads. On my 318ti, the sensor is on the left side, on the inboard pad.
The ABS and brake warning lights will come on in a vehicle when an error is detecting in the he system. This can range from low fluid or pressure to sensor and component failure.
Low brake bressure can be caused by a worn accumulator, poor pump performance, a bypassing brake booster or an inaccurate pressure sensor. To test your brake accumulator, turn the key to the on position and pump the brake pedal. A properly functioning accumulator will give you 25-30 brake applications before the low brake pressure light illuminates