Unable to reset front brake warning with enough left on the pad

[gnocnuk]

Front brake service warning now is red on my car, and I cannot reset it even with a scanner, error code is 480A11.

However dealer says there are still 12mm on the pad so the pad doesn't need a replacement now. Can I/should I replace only the sensor on the old pads? It doesn't sound right to me...

[CatalinP]

You cannot reset the warning because the sensor has been worned down to the triggering limit. The only solution is to replace the sensor.

[EdgyE36]

Related question - how does the system "know" you need new pads? Is it totally based on mileage?

The CPO checklist lists 7mm. We've driven about 3K miles since purchase, and iDrive is saying we need service in 3K more.

[RED_Y_]

Milage+Sensor, past certain amount of miles it will always say 5K or 3K left until the sensor is broken. Watch this video if you want to know how sensor works:

[Clifton]

Originally Posted by EdgyE36

Related question - how does the system "know" you need new pads? Is it totally based on mileage?

The CPO checklist lists 7mm. We've driven about 3K miles since purchase, and iDrive is saying we need service in 3K more.

I could be wrong, but I seem to recall that the brain/CBS uses mileage, fuel consumption, driver inputs and of course the two pad sensors (driver front, passenger rear) as a fail safe.

The idea with fuel consumption is that that higher MPG translates into highway or light city with fewer stoplights and/or slower speeds. Slower speeds equates to less wear on the pads.

For my driving habits, the CBS started with miles, eg brakes due @ 36K. As I got closer to the standard replacement scheduled, it has adjusted the mileage replacement further out. With 24K miles on the clock, "Service brakes" are showing front in 22K & rear in 14K.

I can only assume the CBS started to factor my driving style via MPG and other driving factor inputs.

[pwrdbym]

There's basically two inputs for the brake warning. The estimation of wear based on the factors mentioned above and then the actual hardware sensor. If your sensor is worn through then it will need to be replaced. Use care even with the new sensor as they're notoriously fragile.
If you never want to buy another sensor you can buy a new one and zip tie it up out of the way. This is of course assuming you can track your own brake wear (you know, like we did it the first 70 yrs). You could also complete the circuit by splicing the wires with no sensor installed as it's just a simple circuit. You can't however leave no sensor installed as it will trip the warning.

[CatalinP]

Why would you do that? You can't afford a brake sensor?

[Clifton]

Originally Posted by CatalinP

Why would you do that? You can't afford a brake sensor?

He is just offering a solution. You don't really need them. If you are doing your own maintenance, why spend money on something you don't really need. Has nothing to do with being able to afford something.

[gnocnuk]

Originally Posted by CatalinP

You cannot reset the warning because the sensor has been worned down to the triggering limit. The only solution is to replace the sensor.

Thanks. One thing I don't quite understand is how the sensor could be worned down while the brake still has enough left? Does it mean someone installed sensor incorrectly?

[CatalinP]

Originally Posted by gnocnuk

Thanks. One thing I don't quite understand is how the sensor could be worned down while the brake still has enough left? Does it mean someone installed sensor incorrectly?

Most probably it was wrongly installed.

[CatalinP]

Originally Posted by Clifton

He is just offering a solution. You don't really need them. If you are doing your own maintenance, why spend money on something you don't really need. Has nothing to do with being able to afford something.

That is not a solution, is just monkey business.
The price of a new original sensor makes it ridiculous to even consider such a shortcut.

[RED_Y_]

Originally Posted by gnocnuk

Thanks. One thing I don't quite understand is how the sensor could be worned down while the brake still has enough left? Does it mean someone installed sensor incorrectly?

May be the sensor connector is corroded or damaged or wire is cut.

[Clifton]

Originally Posted by CatalinP

That is not a solution, is just monkey business.
The price of a new original sensor makes it ridiculous to even consider such a shortcut.

FALSE on both counts.

First, a zip-tie costs ridiculously less than a new original sensor. Second it is a proven solution that works on both the street and the track.

However, without intimate knowledge of working on cars and replacing those overly fragile sensors, I can understand why a person would cry monkey business. The reality is that it IS a solution and it works perfectly.

[CatalinP]

Zip tie maintenance on a 50k+ $ car... Pathetic...

[201]

Is this really a discussion we're talking about a sensor thats 23-27$ from fcp euro with lifetime warranty

[Clifton]

Originally Posted by CatalinP

Zip tie maintenance on a 50k+ $ car... Pathetic...

About the same value you've added to this thead....

[Clifton]

Originally Posted by 201

Is this really a discussion we're talking about a sensor thats 23-27$ from fcp euro with lifetime warranty

It's not about the price. The point made was that if you do your own maintenance you don't really need them. An acceptable alternative is that you leave them plugged in and zip tie them out of the way.

[TheUltimateDrivingManiac]

Originally Posted by Clifton

The point made was that if you do your own maintenance you don't really need them.

Correct. Only cowards need brakes.

[Clifton]

Originally Posted by TheUltimateDrivingManiac

Correct. Only cowards need brakes.

He who uses the brakes most, loses...

[gnocnuk]

So I took a look at the front wheel brake, and what I found seems explaining why the light is on.
It looks someone mangled the wiring of the sensor. The wire is actually touching the inner side of the wheel. No wonder why suddenly the indicator is on.

All these began since the last service visit to the BMW dealer a few weeks ago, and they did perform brake fluid flush. Not sure whether this was intended or not but absolutely unacceptable. This was actually the second huge mistake they have done to my car in the last 3 months...

[1norseman]

The brakes due in X,XXX miles warning is inaccurate and confusing, and should be rethought by the engineers.

If BMW wanted to be smart about it, they should have a two stage sensor instead of a simple one stage. (and they could charge more for the sensor, despite not really being much more expensive...)
First sensor would trigger an update in vehicle status, that would more accurately suggest brakes will be due within X,XXX miles (simple for car computer to create an average wear time), and later on it would then trigger a warning on the dash/cluster, telling owner they will need to set up appointment asap.

Would be a lot less confusing for most non mechanics, and less waste of time for mechanics/ service advisers having to explain how inaccurate the warning is...

[Clifton]

gnocnuk - What wheel did you take that picture from? Passenger Rear? Regardless, something is definitely not right, you can see the wire making contact with the wheel and burning through. If it is the brake wear sensor, which it appears like it is, then it shorting out as designed and throwing the code.