Rear brake pad sensor won't allow me to reset

A week ago, my rear brake pad due warning was displayed.

And, for the front, it was 17000km to be due.

Anyway, I decided to replace them both along with new brake wear sensors.

As I was changing them, I noticed that the rear brake sensor was not worn in any way, it was untouched but that was the axle that showed the due warning, I think it was based on the mileage.

However, the front wear sensor has touched the rotors and worn a bit, but it was not showing any error message.

Anyway, I replaced them all and I was to reset the front sensor from ISTA successfully, but it won't allow me to reset the rear sensor.

Additionally, when reading the error codes from ISTA, in front of the DSC module, it shows me a wrong mileage which is 524280. And I found that it can be a bug in BMW software.

After I failed to reset, I tried to correct the CBS data, but it too keep failing.

So, is anyone out there who can help me with this?

TIA

I didn't use ISTA to reset the CBS data last time, but had a similar issue. After replacing the sensor, resetting the CBS data, and clearing codes, I turned the car off. When I took it out for a drive later, it cleared up on its own.

Ximian wrote

I didn't use ISTA to reset the CBS data last time, but had a similar issue. After replacing the sensor, resetting the CBS data, and clearing codes, I turned the car off. When I took it out for a drive later, it cleared up on its own.

Hi,

Thank you for your response.

Can you please recall how did you reset the CBS data and error codes? Through the instrument cluster?

In my case, only the rear axle won't allow me to reset

And after trying, I have driven the car for a few hundred miles already, it still hasn't cleared the error.

Additionally, the hand brake light is illuminated on the dashboard in red for all these times.

nuwaus wrote

Hi,

Thank you for your response.

Can you please recall how did you reset the CBS data and error codes? Through the instrument cluster?

In my case, only the rear axle won't allow me to reset

And after trying, I have driven the car for a few hundred miles already, it still hasn't cleared the error.

Additionally, the hand brake light is illuminated on the dashboard in red for all these times.

I think I used Carly to update the CBS data and reset codes. I would double check the brake sensor wire in the rear if it's still lighting up. If you have the old one sensor cable, try the method of splicing the two wires together to make sure it's not a new defective sensor cable - https://www.m3post.com/forums/showthread.php?t=319185

Ximian wrote

I think I used Carly to update the CBS data and reset codes. I would double check the brake sensor wire in the rear if it's still lighting up. If you have the old one sensor cable, try the method of splicing the two wires together to make sure it's not a new defective sensor cable - https://www.m3post.com/forums/showthread.php?t=319185

The old sensor has not touched the rotor and I tried the wire-shortening method too, but that didn't work either.

Now my last resort is to check the wiring for a rat attack, I think that is possible because there are some symptoms to prove there is a rat nearby.

Ximian wrote

I think I used Carly to update the CBS data and reset codes. I would double check the brake sensor wire in the rear if it's still lighting up. If you have the old one sensor cable, try the method of splicing the two wires together to make sure it's not a new defective sensor cable - https://www.m3post.com/forums/showthread.php?t=319185

As I mentioned, I finally concluded that it was a rat attack.

One of the sensor wires was bitten at the rubber groumet.

So I re-connected the wire and reset was possible. Then I restored everything after spraying some rodent repellents.

I had a similar issue. I replaced my front pads and new sensor and forgot to reset the mileage. When the mileage ran out it wouldn't let me reset even though I had recently replaced it. I read somewhere (maybe on here) to replace the rear sensor and reset the rear so I did that then I was able to reset front interval after.

Since then I also just hard wired the sensor wires together because I'm installing a BBK and that also lets you reset because the car thinks there is a new unworn sensors aka new pads all around.

HuckM3 wrote

I had a similar issue. I replaced my front pads and new sensor and forgot to reset the mileage. When the mileage ran out it wouldn't let me reset even though I had recently replaced it. I read somewhere (maybe on here) to replace the rear sensor and reset the rear so I did that then I was able to reset front interval after.

Since then I also just hard wired the sensor wires together because I'm installing a BBK and that also lets you reset because the car thinks there is a new unworn sensors aka new pads all around.

For me, it was clearly the rat attack. After fixing the wires, it let me reset the counter.

After about 2 months, it popped up again, prematurely. Same symptoms and it would not allow me to reset the counters.

So I checked again and the bloody rat had bitten the same spot again. Now I have fixed it again and reset it.

Now it's OK again, until it bite my wires again, lol.