Welcome to Tech Talk, where our resident BMW tech Nick Owen answers all your pressing BMW technical questions, frustrations, and issues. Have a question for Nick? Email him at techtalk@roundel.org. Let’s get into it.
Comfort Access Issues
I have a 2021 BMW 430i (G22) VIN WBA53AP01MCG74655 with comfort access option (S322A). It worked well until a few weeks ago. Now, no aspects of comfort access are working.
I got error codes: 80410B – Driver LF antenna line disconnected and 804136 – Touchless deactivated.
I went through this diagnostic series:
- Driver and Passenger doors CA are dead
- Trunk CA is dead
- Rain/light sensors still work
- No low‑voltage symptoms
- No fuse failures
- No global BDC faults
- No IBS faults
- No partial CA function
Yesterday, I got a delivery of a used driver outside door handle and installed it. It was reportedly working prior to the vehicle being dismantled. After installing it, I had the same symptoms. So, I uninstalled the replacement and reinstalled the original door handle.
Today, I double checked my OBD II reader and got 80410B again–Driver LF antenna line disconnected. I am now unsure of what else to do to solve this puzzle. Any suggestions are appreciated.
Dene AKA Doc Fjord
There is another antenna you missed, it’s not the door handle. I want to say it’s in the side skirt or under the entry plate that says “BMW”.
E82 128i Brake Light
My car is a 2013 128i. It is an N52 engine with a manual transmission, and the last seven of the VIN are VM55229. It had the performance brake package installed back around 10,000 miles, and it currently shows about 108,000 miles. I change my wheels/tires in the spring and fall, so I do inspect the pad status twice a year. Recently, I had the red “BRAKE” message illuminate along with the red ‘car on a lift’ symbol. I took the car to my independent shop, and after a few minutes inside the car with the key, he was able to clear the “BRAKE” message as well as the symbol. He said it might come back.
It has, and when I toggle the stalk button through the various functions (key inserted although I do have comfort access; wait long enough for most of the indicators to disappear) to see the red ‘rear brake’ symbol, I then push the button on the end of the stalk and see the rear of the car, brake symbol, and -90 as a mileage (?) overdue measurement. These are all in red. I have tried a couple of suggestions found online but can’t get the symbol to disappear nor to reset the pad life mileage. If I hold the trip odometer button for 10 seconds or so, I get into some submenus in German, showing the last seven of the VIN, the CAN configuration, and some other data if I repeat pressing that button.
Please, could you provide the sequence of steps to clear this and reset the mileage for at least another 10,000 miles?
Tom Yee
Wenham, MA
(Multiple emails back and forth about the procedure to reset via the cluster)
I took the 128i to my independent shop. My usual tech hooked it up to the portable computer and discovered that there is an issue with the rear brake pad sensor. I am considering options for rotors and pads, and at that time (which could be months down the line as they are well within spec currently), I will also replace the sensor.
Meanwhile, when I do my winter wheel/tire changeover in a month or so, I will look at the sensor to see if I notice anything particularly obvious. I know it is not hooked into the pad and has not been for quite some time as the spring holding the sensor must have dislodged.
My brake situation is complicated a bit by having the performance brake kit (six-piston calipers and two-piece rotors from 135i; rear caliper with larger piston from E9x 328i but same stock size pads/rotors). I have used EBC Red Stuff pads. They have been fine for street driving but don’t tolerate heat well enough to use for autocross or track use.
I had installed drilled/slotted rotors to replace the kit maybe 50,000 miles ago, but it is a bit more difficult to find matching front/rear pads now. Additionally, the rotors were ECS made by Stop Tech, which no longer really exist (there is an option for rear rotors, drilled/slotted, for about $500/pair that is not reasonable). I have a set of front two piece rotors (OEM Pagid, I think) that are drilled and slotted (but not directional) as the Perf. Brake Kit included but am trying to secure rears. I’ve looked at ECS, BW, FCP so far without a lot of options.
Any suggestions for lower dust street pads that have good initial bite, heat resistance for occasional track or autocross use, and are relatively rotor-friendly?
Tom
As I suspected, there was something preventing you from being able to reset the light. If there is a fault with the brake pad sensor, it will need to be rectified/replaced in order to clear the light. This is possible on the E8X chassis. The car has calculated that you should be due for brakes but since the sensor is tied back, the car does not know. A CBS correction or reset should rectify this and your indy guy should be able to perform that correction.
As for recommending a brake pad that does it all, it does not exist. You cannot have a brake pad be low dust but perform well for street/autoX/track. It just doesn’t work like that. The more performance you want from a brake pad, the noisier and dustier it’s going to be. I cannot recommend or advise on a brand because:
- I don’t know your driving style and how much you actually use the brakes
- No one is paying me to plug their brand
- Recommend looking into getting some cooling to the brakes to help keep the fronts cooler over extended use (autox/track)
- Front brakes do about 75 percent of the braking, while the rear does about 25 percent. You don’t need to have matching front and rear brake pads to get better braking. Sometimes having a strong front pad and a light to medium rear is a way to induce a sense of brake bias and thus improves the overall braking of the car.
My point here is that there are so many different brands of pads out there that it ends up becoming personal preference based on use and satisfaction. I cannot tell you how many conversations I’ve been a part of or overheard about this “pad vs this pad.” Yet the applications, driving styles and cooling abilities are all different. On the race cars, our pads don’t have a brand name. But it’s because they are very specific to our application (endurance races). You may have to try a few different brands to see what you like. A lot of members do this in the parking lot before and after an AutoX/HPDE.