VW Beetle Forum banner

Brake light on - pads good

14K views 7 replies 4 participants last post by  VDubYah  
#1 · (Edited)
Car is 2000 manual.

The brake light is on now since a while.
Pads inspection show 'good' (change less than a year ago).

How does the pad wear indicator work?
Can I disable it by (depending on the circuit layout):
- short to ground
- short to +12V

What else can cause the light to come on?

Will VAGcom or OBDII pick it up?
 
Discussion starter · #3 ·
Brake lever released, yes.

Found:

Brake pad wear indicator

Brake pad wear is measured electrically.
When the brake pad has reached its wear limit,
the contact loop is broken and the alarm
indication lights up in the dash panel insert.
Depending on the model, the “Check brake pad“
warning appears on the dash panel insert
display or an acoustic warning sounds (Audi).

The brake pad wear is checked on the
inner pad of the front left wheel.
When the wear warning is activated,
you must also check the pad thicknesses
of the rear brakes, of course.

The simple circuit diagram seems to indicate that the sensor looks for continuity through the pads; when worn, the circuit gets interrupted.

This would mean that connecting the 2 leads of the front left wheel sensor connector/wires should 'kill' the light.

Also: bad/corroded contacts (or broken wires) will trigger the warning light even so pads are good.
 
Discussion starter · #6 ·
The warning light I am referring to is bottom right in the dash (5 o'clock position). Manual refers to the light as front brake pad warning light.

Checked front left brake pad connector. Shows open circuit across the sensor on the connector.

I connected both pins (closed circuit), light is still on. (I assume the light looks for closed circuit, and wearing the pads will break the circuit).

Is there another sensor on the front right as well? I thought I read only the front left is monitored on the 2000 Beetle?
 
Discussion starter · #7 ·
Brake pad wear indicator light

Still on. Need to get rid of it.
I assume wear indicator looks for 'open' circuit'. Measuring across the connector, it shows open (so the ECU says "pads worn").
When when I shortened the connector (on the car side, which should 'close' the circuit), it stays still on.

On other cars (B5 A4 IIRC), it is possible to 'code out' the sensor.

Does anyone know if it is possible on the 2000 Beetle as well?
If so, what are the softcodes (VAGcom)? I assume in the instrument cluster (?).