Front Brake wear sensor

[Aero]

HiWould like to seek some help and advice about the brake wear sensor.Nees some help in advicing on how to connect the wire from the sensor to the car, as the previous owner has deleted the use of the sensor and has cut the wire and now only left the wire from the car without any connector.The wire from the sensor only has two wire and the wire coming from the car has three and they are in brown,yellow and blue.Which i dont know each colour are for what...........Thanks in advance.

 

[astroboy]

The wire is just to provide a return ground signal to close/complete the pad wear indicator circuit. It's single wire connected to the dash where the +ve is already waiting at the indicator bulb. Puncturing of the pad wear sensor will complete the ground signal to light up the indicator bulb. Simple elementary 12v circuit.

 

[Aero]

Ok, noted, but which wire should i use, yellow, blue, or brown. Do you know why is there 3 wire instead of 2.

Thanks

 

[astroboy]

Ok, noted, but which wire should i use, yellow, blue, or brown. Do you know why is there 3 wire instead of 2.

Thanks

So many wire meh? Need to check with jarance if that's the case, he has the wire diagram for most BMW.. :wink:

 

[Aero]

That why i need you guys assistant, as the pad sensor only got 2, if the car wire also 2 then just mate it loh, but on the car it has 3.

Guess i need to wait for someone that can assist.

 

[jarance]

There are two sensor for brake wear sensor.

1. Left Front
2. Right Rear.

Right rear wiring should be Brown - Yellow. The brown wire is always ground.
The right rear yellow wire is wired to the left front sensor which is colour as yellow - yellow.
The yellow wire is wired to the instrument cluster.

basically they are wired in series.

if the yellow wire is open circuit, the alarm will light up at the instrument panel.
It have to be shorted to ground in order to clear the alarm.

 

[astroboy]

Ini macam ka?

 

[mizhan]

no wonder i just pay people to do... too much to understand

 

[Aero]

Well does these mean there should be 2 set of wire, which one set for the front and another for the rear.

rear [yellow, brown]
front [yellow]- routed from the rear yellow

is that what u mean.

But i only has front disk, which mean i dont have a rear sensor. and if i were to install a rear disk set i need to route my current brown & yellow from the front to the rear disk ? [correct me if i am wrong]

My current location of the wire is in the front wheel well and i has 3 wire, which is blue,yellow and brown, the previous owner has short two of the wire to stop the warning light, cant remember which one,
so how come my car has 3 wire in the front instead of just 2 like u have describe.

By the way mine is a m40.

Thanks

 

[jarance]

ahhh.. your is front disk and rear drum.. if rear is drum type brake, then just look at the brown and yellow wire at the front.

 

[jarance]

no wonder i just pay people to do... too much to understand

bang, your e30 is a special one. Only specialist is allow to handle it.

 

[astroboy]

.. the previous owner has short two of the wire to stop the warning light..

The answer to your question is in your above posting. Just locate these 2 wires, open it up and connect to a brake wear sensor, kao tim lor!

..and all these years.. I thought it's a close circuit that trigger sensor to illuminate, which was wrong.. learn something new today! :top:

 

[Aero]

I did thought of doing that, but dare not experiment on it, as it is still a bmw it may be a expensive lesson, that i i need to check and confrim first. But then what about the third wire, what it is for???

Cheers astroboy

 

[jarance]

I did thought of doing that, but dare not experiment on it, as it is still a bmw it may be a expensive lesson, that i i need to check and confrim first. But then what about the third wire, what it is for???

Cheers astroboy

bro, you could be looking at the wrong wiring connection. if it is 3 wires, then the connection is for the ABS speed sensor control. brake sensor is only 2 wires.

 

[Aero]

hmmm but i dont think mine come with an ABS as i dont see any pump or sensor around the car that pointed out a ABS......

The wiring is on the front right wheel.

That what i think too so meaning mine do not come with a brake sensor ???

cheers

 

[jarance]

hmmm but i dont think mine come with an ABS as i dont see any pump or sensor around the car that pointed out a ABS......

The wiring is on the front right wheel.

That what i think too so meaning mine do not come with a brake sensor ???


cheers

BMW always install the brake sensor on the FRONT LEFT.

If the wiring is on the front right then, it is definitely not the brake sensor.

ABS speed sensor are installed for all 4 wheels. Since you dont have ABS, then the wiring is NOT for ABS.

mmmmm.. what else is installed at the wheel. BTW, what model is your ride and year?

and did the previous owner did an upgrade of the engine with engine harness.

 

[jarance]

Didnt reliaze that there are brake pad sensor for the drum


Rear wheel brake-brake pad sensor - BMW parts catalog

and for front (normal)

Front wheel brake-Brake pad sensor - BMW parts catalog

 

[astroboy]

.. mmmmm.. what else is installed at the wheel. ..

I know front right wheel arch has a thermo probe to measure external temperature in the E39..

 

[Aero]

i doubt he has change the engine before, am driving a m40 1989 sedan.

 

[jarance]

can you post some picture of the brake area and engine compartment? It might help.