[xBr0k3n]

Hi all,

As the title says I have a red service icon for front brake pad wear, telling me to go to the nearest dealer. Car is an ‘07 335i.

I run aftermarket AP brakes and have had the brake sensor bypass(closed loop connected) for the whole 10 years of ownership. I let the brake pad wear on the computer go into negative numbers, by like 15 miles, as I kept being lazy and not just resetting it. Pads probably have like 10k miles left on them.

Since the numbers went negative I can now no longer clear this myself it seems - I’ve always normally done it when I change the pads or when it’s nearing 0. I’ve done the usual reset on the dash but it just set the front pads to - - - -. In doing this it has now also set the rear pads to - - - - even thought it has nothing to do with them. I read something, somewhere, about the DSC and KOMBI disagreeing or some ‘CBS’ (not sure that’s right?) that needs running.

My version of ISTA shows the fault as 005DE0. I’ve tried running the CBS correction and the values in ISTA now show 255% 40000km but the car still shows the dashes. I’ve also disconnected the pad sensor bypass to throw an open circuit, left it like 20/30 seconds with the ignition on, then plugged it back in and cleared codes. Still nothing. I’ve checked the bypass is still a closed circuit and it is, it would also be super coincidental timing.

What can I do to clear it?? Super annoying the car donging and having the red warning illuminated. It also keeps the red handbrake light illuminated when driving.

[mrjimyjohn]

If CBS cant be reset through the usual method (ignition on, engine off), it probably means one of your 2 sensors isn't shorted. I believe if either axle goes negative then neither can be reset until the sensor is replaced (or shorted).

[xBr0k3n]

My understanding is that the pad sensors are a closed circuit and when they wear they become open. So simulating this by just removing and replacing the wear sensor bypass should fix it? As I said I’ve done this and nothing changes.

[Mojo_jojo77777]

your best bet is to code out CBS.
I cant remember what all in module, but CBS_Brake (or whatever its named), there was option to "Hide" instead of display.

Years back, I went through module to code out all maintenance reminders since my mileage was up there, and the module starts acting funny after 20+ oil changes.

You essentially hide.nicht activ CBS variables until they stop displaying in idrive.

[xBr0k3n]

How do you code that out is that with Tool32/NCSEXPERT? I have a copy of INPA too but it’s very old and has v6.00 files and it won’t talk to most modules as it says I need v21.00. Are their negatives to disabling these at all? Mileage is something like 123k now.

Just for sanity I did the same test/clears and still the errors persist.

[Mojo_jojo77777]

I personally use Protools, which arent standard coding parameters. They required going into the deeper coding that was all in German (what Im assuming is what NCSEXPERT can do).

https://www.1addicts.com/forums/show....php?t=1312512

thats good link to read through, and should give better idea what I'm trying to say.

[xBr0k3n]

That for the information. I had more of a look through Tool32 now I got it working properly, again, and I found that it still shows the front sensor as 'nicht ok' which is a tad weird as the likelihood of this going bad just as the discs went under 0 miles is extremely low.

So from the 'status_cbs_sensor_bbv' it shows:

Satz : 1
JOB_STATUS = OKAY
STAT_CBS_BBV_SENSOR_VA_TEXT = nicht OK

VA being front axle.

Then from the 'status_cbs_bbv_dicke' it says the brakepad thickness is below 0 (I had ChatGPT tell me what the value actually meant):

Satz : 1
JOB_STATUS = OKAY
STAT_CBS_BBV_DICKE_VA = -5.120000E-006

I'm going to test the bypass sensor again when its not chucking it down and read the resistance rather than check continuity to see if perhaps the resistance is too high.

[xBr0k3n]

Ok so I finally got some time to look at this some more.

I bought an £8 brake wear sensor from Amazon and with this attached to the car I could reset the warnings. I swapped back to my bypass and it would give plausibility but only a yellow icon.

When I initally tested the continuity of the old bypass I did it with the car on the ground reaching in with the wheels at full lock, this put the wire in an odd angle and must have connected the broken connection and therefore giving me continuity. When I put the car in the air and pulled the wheel the bypass sensor had a split in the green wire. Stripped it back and soldered it back together and jobs a good'n.

So yea coincidental timinig was the cause of the persistent error.

Now I have fixed that my FRM2 has finally decided to fail so my indicators blink at lightspeed and all my bulbs are 'broken/shorted' yet working fine :'(