Brake wear sensors

[gchristofi]

I have the "check brake linings" message ever since I decided to amuse the kids by driving fast through a bumpy field to bounce them around (yes I know... it felt like I might be making an expensive mistake at the time! then again, on the plus side, my stupidity means that on searching for the sensor problem, I found the 2 split front CV boots which will be replaced and hopefully avert CV joint failure.)

I've checked for obvious damage to the sensors but can't find any. I just need to confirm a few things to continue diagnosis...

1) am i correct in thinking these are sacrificial sensors? i.e. one the pads reach the end of their life, the disc wears through the sensor, creates an open circuit which triggers the alarm signal

2) once the circuit is complete again (by replacement sensor or jumper), should the warning reset itself automatically?

2004 4.4

[gmc15]

They are sacrifical sensors - ( they are on the front near side and rear off-side).

Here is a link on how to reset the warning on the dash

http://www.ehow.com/how_4844864_check-b ... e-bmw.html

Graeme.

[gchristofi]

Thanks for that link Graeme, worked a treat. I decided the quick test was to cut the sensors near the plug and use the plug to make jumpers, with a 50% chance of finding the correct one 1st go. Sods law it wasn't the 1st one I tried, nonetheless, warning has gone and 2 sensors on the way. Will be keeping my new "custom made brake wear jumper plugs" for next time it happens...