Re-using old brake pad wear sensor

[325_driver 422]

Ill probably end up replacing it, but for the sake of curiosity

Is it possible to reset the brake pad wear service interval and then re use the old sensor as it's in good condition.

Do you jump the two wires to reset it, and then install the old sensor? 

Just wondering if anyone has done it.

Cheers

[Eagle 1515]

E90 has a 2 stage sensor i think - one stage for condition\k's remaining in the OBD service menu and the another to trigger the light on the dash when they are low. I suppose you could reuse it but the condition estimate probably wont be accurate im assuming, but it should reset in the OBD service menu

I just cut the sensors after the plug, join and solder the 2 wire together and hide them where you can't see. It's an idiot feature really, no one who does their own maintenance work needs it. 

[325_driver 422]

@Eagle 

Thats sort of why I was saying it, even so if someone let's brake pads get that low it would suggest they haven't visited a wof or mechanic ever lol

Besides I didn't even think the rotor touched the sensor until the pads get down to like 3mm it would look like and then it starts wearing on the sensor.

Or is sensor usually the same thickness as the new brake pads when they are new?

[Eagle 1515]

Id say it is and starts wearing immediately unlike the older type which only became truly worn once you ran the pads low enough to cut the signal. The low light does come on fairly early, i tend run my pads down fairly low especially if are expensive compounds.

[325_driver 422]

Just got rid of the error and reset the brake warning interval.

For future reference if anyone else is wondering,

I read a few places that, apparently if the yellow warning light doesn't come on then the old sensor is re-usable, but i can confirm that this is not entirely the case.

It would appear that the computer obviously has a range of resistances that it would qualify as a "new" brake pad sensor that it would accept.

I.e. i reset the light by bridging the pins with a paper clip at the plug, no errors on the car

then when i plugged the old sensor in (which triggered no warnings on the old pads, still 4,000km to go) and it threw up the red hoist inspection light straight away.

So in the end i ended up just bridging the two wires, and all is well.

I wish i knew how touchy it was, as i've made about 5 separate orders @ RM european / FCP and they cost F all over there, vs 50 @ part master and quoted $80 at the dealer.

So lesson being, if you do your own maintenance, always have spare new rear/front brake pad sensors in the inventory.

Does anyone know if it is a legal requirement for those sensors to be present? i.e. if it were removed entirely by bridging it neatly at the box permanently?

@Eagle do the kms on the service interval still countdown correctly without the sensor?

Edited September 19, 2019 by 325_driver

[Eagle 1515]

No legal requirement for pad level warnings. No idea about the service interval myself.