Problem with Pad Wear Sensors

dnvrdrvr wrote

You have 4 sensors? I only have 3. Two up front and one on the passenger rear.

FWIW, when I change my pads for taking the car to the track I have an extra set of sensor "capsules" with the actual sensor & line snipped off that get plugged in. It keeps the warning lights from coming on. Don't know if that helps determine open or closed system..?

Can you explain more in detail or have pictures perhaps? I'm going with a BBK soon and find this interesting. Hopefully avoiding the same issue.

I gather that you have "new" sensor clips? And when you replace the pads you install new wear sensors? I'm confused on the "sensor & line snipped off taht get pludded in." You wrote, what does that mean?

Thanks,
Rob

BimmerRob08 wrote

Can you explain more in detail or have pictures perhaps? I'm going with a BBK soon and find this interesting. Hopefully avoiding the same issue.

I gather that you have "new" sensor clips? And when you replace the pads you install new wear sensors? I'm confused on the "sensor & line snipped off taht get pludded in." You wrote, what does that mean?

Thanks,
Rob

Hmm.. how to explain. Maybe this image will help (taken off realoem).


Last season I ordered track pads for the front and they just happened to come with a set of sensors. The sensors with my OEM pads are fine so we decided to clip off the actual sensor piece on these extra ones so all that's left is what I've outlined with the blue box. (The tip of the line is wrapped with electrical tape.) Just pop the cartridge into the housing and that seems to make whatever connection is necessary to keep the warning lights off... Does that help? I'll take pictures & post them tonight if not.

Edited to answer your second question ("And when you replace the pads you install new wear sensors?"): When I put the OEM brakes back in, we re-use the original sensors. I'm on & off with the brakes enough that I know what the pad wear looks like, but if I had to take into the dealership, I wouldn't want them to question anything.

Just found this in the DIY section too
http://www.m3post.com/forums/showthread.php?t=319185

OMG... thank you so much for that link

so basically just cut the sensor wire near the black box and twist the two wires together that are inside the cut sheath.. I'm going to try this tonight and I'll let everyone know

--mike

dnvrdrvr wrote

Hmm.. how to explain. Maybe this image will help (taken off realoem).


Last season I ordered track pads for the front and they just happened to come with a set of sensors. The sensors with my OEM pads are fine so we decided to clip off the actual sensor piece on these extra ones so all that's left is what I've outlined with the blue box. (The tip of the line is wrapped with electrical tape.) Just pop the cartridge into the housing and that seems to make whatever connection is necessary to keep the warning lights off... Does that help? I'll take pictures & post them tonight if not.

Edited to answer your second question ("And when you replace the pads you install new wear sensors?"): When I put the OEM brakes back in, we re-use the original sensors. I'm on & off with the brakes enough that I know what the pad wear looks like, but if I had to take into the dealership, I wouldn't want them to question anything.

Ah! Much more clear now. Thanks! That link you attached, I saved that and had read through it before so now I'm puting 2 & 2 together. So basically you did what that link shows? And leemik posted the same thing I think. But if I'm following correctly, you're basically just re-installing the sensor line to the junction box? Probebly be a bit more clear when you post those other pics. Thanks man!

Yep, here's a photo of my track "sensor".


You phrased it perfectly, you'll need to "re-install the sensor line to the junction box". LMK if you want add'l photos under the fender... it's easy enough to pull the wheel off.

Ok cool. Now makes sence. But I'm also a bit confused. If you cutt off the rest of the wiring to the brake pad sensor clip, splice the wires, tied them (soderd) together as you did, then when those two wires make contact with each other, wouldn't that trip the sensor light just as if the clip sensed the pads were worn down? I saw the brand new wiring and clip at the dealer ship parts store yesterday.

So I got to see the white capsul box you show above with the wire. Since there are two leads or wires, I thought they would have to stay open looped in order to not trigger the light.

BimmerRob08 wrote

Ok cool. Now makes sence. But I'm also a bit confused. If you cutt off the rest of the wiring to the brake pad sensor clip, splice the wires, tied them (soderd) together as you did, then when those two wires make contact with each other, wouldn't that trip the sensor light just as if the clip sensed the pads were worn down? I saw the brand new wiring and clip at the dealer ship parts store yesterday.

So I got to see the white capsul box you show above with the wire. Since there are two leads or wires, I thought they would have to stay open looped in order to not trigger the light.

Hmm. I'm not an expert, so take this with a boulder of salt. Based on the fact that I know the above works (those babies were in & out more than a dozen times this summer without issue), my guess is the warning is triggered when the connection is lost between the two wires.

dnvrdrvr wrote

Hmm. I'm not an expert, so take this with a boulder of salt. Based on the fact that I know the above works (those babies were in & out more than a dozen times this summer without issue), my guess is the warning is triggered when the connection is lost between the two wires.

Yep, that makes sence because you tied them together making contact so that makes sence. I'm installing my BBK this weekend. So I wonder if I should just tie the sensors off or go ahead and cutt them then splice and connect the two leads like you did to the white plug-in housing of the sensor cable.

I'm curious though, you said you those babies where in & out a dozen times. Why do you have to remove and replace the plug lead if the wires are cutt off and tied up? I figure once the sensor cable is cutt off and leads tied, you can just leave it as is for the life of the car. That would be ideal with a BBK.

Thanks,

BimmerRob08 wrote

Why do you have to remove and replace the plug lead if the wires are cutt off and tied up? I figure once the sensor cable is cutt off and leads tied, you can just leave it as is for the life of the car.

I put these in when I'm out at the track with my track brake pads (PFC01), put the full sensors back on when I put my OEM pads back on for daily / street driving.

You could (and I would think you should) just keep the cut sensors installed.

BimmerRob08 wrote

Yep, that makes sence because you tied them together making contact so that makes sence. I'm installing my BBK this weekend. So I wonder if I should just tie the sensors off or go ahead and cutt them then splice and connect the two leads like you did to the white plug-in housing of the sensor cable.

I'm curious though, you said you those babies where in & out a dozen times. Why do you have to remove and replace the plug lead if the wires are cutt off and tied up? I figure once the sensor cable is cutt off and leads tied, you can just leave it as is for the life of the car. That would be ideal with a BBK.

Thanks,

Just tie the sensors out of the way -- it works and its simple.

Sounds good all, thanks.

rldzhao wrote

Here's some instructions. BMW recommends resetting using diagnosis system, but it is not required.

Resetting the service items

Observe the following process for resetting:

Switch on the ignition (terminal 15)

Press the trip odometer for approximately 10 seconds until the first CBS item appears.
(The next item is reached by briefly pressing the button again)

If the value is to be reset, press the button again for approximately 3 seconds until ”Reset?” appears.

Reset is confirmed by pressing the button again for 3 seconds.

This worked for me. Had my Brembos installed (with the sensor zip tied) for about 1.5yrs and the rear brake pad sensor came up yesterday. Tried resetting using the method above and it worked for me! Thanks rldzhao