[Efthreeoh]

Originally Posted by Aptechguy

I need a lil clarification here ....my front brake pads are worn down quite a bit ...CBS is showing 9000 miles for the front pads ...if I replace the front pads now along with the brake wear sensor ...will resetting the CBS for the front be an issue or will it reset with no issue?

It will be no issue. New pads and new sensor, just reset the CBS.

[Aptechguy]

Thanks

[deputyjk]

Sorry to dig up an old thread guys.

I got the red car on lift and brake system exclamation mark warning lamp this week. In the CBS is shows front pads milage "-----".

I honestly dont know why this had shown up as I havent touched the front pads or reset anything to my knowledge.

Anyway pads have about 50% left on them so I dont need to change the pads.

If I buy 2 new sensors will I be able to reset the CBS for the front pads no problem? Or will I have to snip old sensors and tie wires together to trick system?

Thanks in advance guys.

[ducatiti]

Bump...Would like to learn more about this system. No conclusive info so far for me.

So when I get a red brake light warning for my rear, replace the pads and sensor, I can reset the rear CBS only?

I have read that you have to wait till you change the fronts as well before resetting or you will get the service lift warning thingy.

Can someone confirm this please?

[Efthreeoh]

Originally Posted by ducatiti

Bump...Would like to learn more about this system. No conclusive info so far for me.

So when I get a red brake light warning for my rear, replace the pads and sensor, I can reset the rear CBS only?

I have read that you have to wait till you change the fronts as well before resetting or you will get the service lift warning thingy.

Can someone confirm this please?

Yes you can reset just the rear axle only. You can reset each axle independently from the other.You have to be in the correct menu item in the CBS (i.e. on the rear axle readout) to reset it.

The CBS keeps track of the wear rate of the pads by the wear on the sensor. The sensor is dual-stage, which means it wears halfway through and records the event in the CBS computer (a loop of wire imbedded in the sensor breaks). There is no notification provided when the 1st loop of wire breaks. The second stage is when the second wire loop in the sensor breaks which triggers the red "Brake" icon. When that happens the CBS menu will show either the front or rear axle at -- miles left on the brake pads. It does that so you know which axle needs new brakes. The sensor is dual-stage so as to provide the CBS with an actual wear rate of the pads, which allows the CBS to estimate the remaining miles left on the pads. However once the 2nd wire loop breaks and the red "Brake" icon comes up, one or both sets of pads are worn out and need replacement.

By trying to reset the CBS and not change the pads and sensor you are just confusing the logic built into the software. Once you reset the CBS, the algorithm in the CBS software assumes you are starting with new pads and a new sensor and starts a new calculation using the predetermined estimated wear rate of the pads before the 1st stage is triggered. If you don't change the wear sensor but reset the CBS, the system still senses the 1st stage (or second stage) is triggered, which screws up the logic. This is why whenever you replace brake pads on a BMW you replace the sensor and reset the system. The system uses a algorithm of a predetermined wear rate along with the real wear rate as determined by the sensor wear rate (the 1st wire loop breaking) to provide an estimate of the miles remaining on the pads. So if you perturb that sequence and not reset the CBS and the Brake Wear System (by using new wear sensors) you screw up the logic of the software in the CBS and the system reports erroneous information. I think most people don't understand the brake wear sensor is a consumable item that gets replaced in tandem with new pads.

__________________

[ducatiti]

Originally Posted by Efthreeoh

Yes you can reset just the rear axle only. You can reset each axle independently from the other.You have to be in the correct menu item in the CBS (i.e. on the rear axle readout) to reset it.

The CBS keeps track of the wear rate of the pads by the wear on the sensor. The sensor is dual-stage, which means it wears halfway through and records the event in the CBS computer (a loop of wire imbedded in the sensor breaks). There is no notification provided when the 1st loop of wire breaks. The second stage is when the second wire loop in the sensor breaks which triggers the red "Brake" icon. When that happens the CBS menu will show either the front or rear axle at -- miles left on the brake pads. It does that so you know which axle needs new brakes. The sensor is dual-stage so as to provide the CBS with an actual wear rate of the pads, which allows the CBS to estimate the remaining miles left on the pads. However once the 2nd wire loop breaks and the red "Brake" icon comes up, one or both sets of pads are worn out and need replacement.

By trying to reset the CBS and not change the pads and sensor you are just confusing the logic built into the software. Once you reset the CBS, the algorithm in the CBS software assumes you are starting with new pads and a new sensor and starts a new calculation using the predetermined estimated wear rate of the pads before the 1st stage is triggered. If you don't change the wear sensor but reset the CBS, the system still senses the 1st stage (or second stage) is triggered, which screws up the logic. This is why whenever you replace brake pads on a BMW you replace the sensor and reset the system. The system uses a algorithm of a predetermined wear rate along with the real wear rate as determined by the sensor wear rate (the 1st wire loop breaking) to provide an estimate of the miles remaining on the pads. So if you perturb that sequence and not reset the CBS and the Brake Wear System (by using new wear sensors) you screw up the logic of the software in the CBS and the system reports erroneous information. I think most people don't understand the brake wear sensor is a consumable item that gets replaced in tandem with new pads.

__________________

Thank you sir. Your post has answered all my questions.

[deputyjk]

Originally Posted by Efthreeoh

Yes you can reset just the rear axle only. You can reset each axle independently from the other.You have to be in the correct menu item in the CBS (i.e. on the rear axle readout) to reset it.

The CBS keeps track of the wear rate of the pads by the wear on the sensor. The sensor is dual-stage, which means it wears halfway through and records the event in the CBS computer (a loop of wire imbedded in the sensor breaks). There is no notification provided when the 1st loop of wire breaks. The second stage is when the second wire loop in the sensor breaks which triggers the red "Brake" icon. When that happens the CBS menu will show either the front or rear axle at -- miles left on the brake pads. It does that so you know which axle needs new brakes. The sensor is dual-stage so as to provide the CBS with an actual wear rate of the pads, which allows the CBS to estimate the remaining miles left on the pads. However once the 2nd wire loop breaks and the red "Brake" icon comes up, one or both sets of pads are worn out and need replacement.

By trying to reset the CBS and not change the pads and sensor you are just confusing the logic built into the software. Once you reset the CBS, the algorithm in the CBS software assumes you are starting with new pads and a new sensor and starts a new calculation using the predetermined estimated wear rate of the pads before the 1st stage is triggered. If you don't change the wear sensor but reset the CBS, the system still senses the 1st stage (or second stage) is triggered, which screws up the logic. This is why whenever you replace brake pads on a BMW you replace the sensor and reset the system. The system uses a algorithm of a predetermined wear rate along with the real wear rate as determined by the sensor wear rate (the 1st wire loop breaking) to provide an estimate of the miles remaining on the pads. So if you perturb that sequence and not reset the CBS and the Brake Wear System (by using new wear sensors) you screw up the logic of the software in the CBS and the system reports erroneous information. I think most people don't understand the brake wear sensor is a consumable item that gets replaced in tandem with new pads.

__________________

Hi Efthreeoh

If you confused the logic by reseting the CBS before changing the pad and sensor, will it reset when you actually replace things?

[Efthreeoh]

Originally Posted by deputyjk

Hi Efthreeoh

If you confused the logic by reseting the CBS before changing the pad and sensor, will it reset when you actually replace things?

If you didn't drive the car then I'd guess yes.

[ducatiti]

I just read the entire thread again and noticed some are having difficulties resetting one axle side only, ending up shorting or installing a new sensor for the other axle.

So the CBS reset function is not independent for the front and rear?

Please confirm.

[Efthreeoh]

Originally Posted by ducatiti

I just read the entire thread again and noticed some are having difficulties resetting one axle side only, ending up shorting or installing a new sensor for the other axle.

So the CBS reset function is not independent for the front and rear?

Please confirm.

They can be reset independently. I've done it 3 times on my car.

[nitehawk]

Bumping this to get some insight...

So is it possible for the break pads sensors to trip too late or not at all?

My mechanic inspected my brakes about 6 weeks ago. He stated that I'm on borrowed time and recommended that I change pads/rotors all around as soon as possible.

My CBS is stating the following currently:

Front 29000km - inner pads look very close to the brake wear sensor. Outer pads have lots of life.
Rear 9000km - these have about 2-3mm left. Should also be right at the wear sensor. See below pic of outer rear pad (right side)

Been waiting for the red warning light to pop-up but it has not. Just trying to understand why the estimates would be off and/or why it would not trigger? This would be the first brake service on the car nearing 140k km's.

I'm going to go ahead and get it all done anyway and not wait much longer as the system doesnt seem all that reliable...

[baybmwmikey]

Newer BMW owner here. My 2009 328i's onboard computer is saying the fronts pads need service in 11k miles, and the backs need service in 19k miles. I visually inspected the pads and the backs are far lower than the fronts, looks like the fronts have about 70% life and the backs have about 20%.

How could this be? If I replace the back pads and rotors but not the sensor, and don't reset the computer, will it stay at those levels until the pads wear down to the level the sensor is currently reading at? Or should I just replace the sensor while I'm doing the backs and reset the computer for good measure?

Thanks in advance.

[89mustaine]

I've got the constant "brake" in Yellow on the dash currently. I've put 50k on the car in the last 18 months so I figured it was legit so I took it in, shop just called and told me the front brakes still have +50% and the rears have even more left. Apparently the rear sensor is broken though. They said, a new sensor can't be installed however because they wear with the pad from the beginning. So what do I do?

I've seen some info on here about cutting and splicing and some who trick the system somehow. I'll experiment with these but it seems like a band-aid to me.

Thoughts?

[jnoyolapicazzo@yahoo.com]

I'll be honest, I'm very confused by the different sequence on how things are supposed to be done. So let me tell you what I did and I would appreciate help to fix my problem, even if it's been answered, just because I'm confused...

Rear sensor wore out a few weeks ago and I got the red car on a lift and brake light on. I replaced the brakes, but didn't have a sensor available at the moment, so I left the old worn out sensor (it was worn out completely). Turned on the car and tried to reset the brake indicator. It didn't go away obviously because the sensor was still worn out. Few days later I get the sensor and find some time to put it on. Installed, tried to reset the indicator, but still won't reset. What am I doing wrong and how can I fix it? I've tried to reset both from the dashboard as well as using the Carly BMW app. The Carly BMW app tells me it's a fault on the rear wheel brakes.

HELP!!

[Mike-3366]

Originally Posted by 3Coupe4Me

I made the mistake of resetting the the brake mileage when I changed my rear brakes and sensor. I ended up getting the "car on lift", brake warning light and "----" miles indicated for next brake change After reading the different threads and Bentley manual stuff on this I finally found a way to fix this.

The system looks for two "untriggered" sensors when you reset the brake service mileage. If it sees even the preliminary trigger on any of the sensors it will give you this error. The preliminary trigger as stated above does not mean that there is no brake pad left. In my case the front pads had at least a little under 50% life left in them and therefore I did not replace them or the sensor. So this is what I did to fix it.

I took the old sensor I just removed from the rear and cut of the sensor portion. I then stripped the two wires back and twisted them together which creates a short and mimicks the reading a new sensor gives. Unplug the partially used sensor at the socket connection on the car (not the brake) and plug in the shorted old sensor. Do the brake reset procedure and you will get the appropriate mileage restored. Go back and remove the shorted sensor and plug back in the partially used sensor. At this point everything should be back to normal with the new sensor showing 90,000 miles and the partially used sensor showing whatever miles that were there before you created the error.

Hopefully this helps you. I think you should be able to use this procedure to reset the front or rear sensor one at a time without having to replace both sensors.

So i am hoping to do what 3Coupe4Me describes above on Sunday, expect I will not install a new sensor and will strip the two wires on BOTH sensors, mimicking the reading of a new sensor on front (even if I did not replace the pads ) and back. Since I am changing my own pads I do not want the sensors, I just want the "Car on lift" and "Brake" indicators to go! Do you see any big mistakes in my plan? Ducatiti, have you been able to decipher this topic? do you have any hints?

[Mike-3366]

So I did cut the brake sensor off the back wheel, connected the blue and white wire together and the "Brake" light and car on lift symbol did NOT go away.

[Wolf 335]

Originally Posted by Mike-3366

So I did cut the brake sensor off the back wheel, connected the blue and white wire together and the "Brake" light and car on lift symbol did NOT go away.

You will need to reset your brake service interval.

I cut both of my sensors, connected the wires and reset. All good.

[Mike-3366]

Originally Posted by Wolf 335

You will need to reset your brake service interval.

I cut both of my sensors, connected the wires and reset. All good.

Wolf, thanks, the key here is BOTH!!! sensors. After that I followed this video

to set the intervals and I am all set, PARTY!!!!

[hardr85]

This may have been covered already, but I didnt want to read every post. I took my sensors off the caliper and zip tied them up. I figured out your brake/service light wont reset unless you unplug the sensor and plug it back in so the car thinks you have changed the sensor. It is a bit of a PITA, but i dont need a computer to tell me when to change my pads, and I am not going to spend and extra 30$ for every pad change for nothing

[msh441]

I have about 85% left on my brakes and got a front trip. Vehicle on lift with a 600 mile countdown. I'm assuming simply a bad/broken sensor up front.

If I replace the sensor and reset the sevice interval as indicated in the video above, will I be good to go?

Secondly. Confirming only one sensor per axle on the ________ side?

[jp7430@yahoo.com]

I truly appreciate this thread. This saved me a lot of frustration, so, getting to the point. I have a 2008 335i that had both front and rear brake service indications. I replaced the rear pads, as the front still has lots of life, couldn't reset the brake service afterwards, and things actually got worse when I tried. Dash BRAKE light went red always on, Red car on lift service warning when I shut off the engine. Then replaced the rear sensor and that did NOTHING! Here is how I solved, thanks to this awesome thread!

Took old rear sensor, cut off the sensor, stripped and twisted the wires together. Removed front driver side wheel, disconnected front brake sensor from the harness plug and plugged the old rear sensor in and let it hang with wires twisted together. Went through the brake sensor reset and PRESTO! All is right with the world. Simply disconnected the old rear sensor, reconnected the front sensor, reinstalled the wheel. Took her for a drive, then re-checked, all green, front brakes showing 17000 miles, rear showing 60000 miles, so after the drive, the system updated life remaining on the front.

I hope this helps