[jehill]

I found this solution by Mark333032 in Bimmerpost, used for a different BMW model. Many thanks.

"Open the Bimmercode app and go to Instrument Cluster/Expert Mode/3301 CC_ID_Sperre/CC_ACTIVIERUNG_5/Custom Value. You should see 'FF' listed in Bytes 0 to 7. Scroll to Byte 5 and change it from FF to F7 and press 'Done'.
Then back out to the 'Instrument Cluster' menu and hit 'Code'. The 'SOS Call System Failure' message is now gone. The only thing the car asked me to do was reset time."

This worked perfectly on my F39 to eliminate the very annoying "Emergency call malfunction" error message on the dashboard. This is most often caused by a dying TCM battery which is located under the shark fin and extremely hard to replace because you need to remove panels and lower the headliner. The replacement battery costs about 65 USD but the BMW dealer charges an additional 400+ USD for service to replace it. Batteries last 3 - 4 years (or less depending on climate) and you will then need to replace again.

This was my first use of Bimmercode but it ended up being easy, only a one byte code change. I used the Vgate iCar Pro Bluetooth OBD2 Code Scanner to connect Bimmercode to my car, about 32 USD on Amazon. Only scary part was the dashboard went black after coding and rebooting the ECU. I waited a couple of minutes, turned the ignition off and back on, and everything came back. Just had to redo the time and date in the menu settings.

[chowser51]

lolz. that's what i told you in the other thread as well.

But have you tried a dealership to replace the battery? I thought it was covered. They did mine for free.

[jehill]

Not covered when off warranty. Dealer wanted 480 USD. That's why I reposted. Many F39 owowners have or will have this problem

[Ryan Emad]

Does this affect any functionality other than the SOS call being disabled?

[jehill]

Originally Posted by Ryan Emad

Does this affect any functionality other than the SOS call being disabled?

Nothing else affected that I have seen.

[//TMT]

Does the telemetry use the same antenna? Navigation update downloads?

[jehill]

Don't know. In the past navigation updates have been done while the car was in for service. Since I am off warranty and would have to pay for the updates, it is not worth it to me. Maybe someone who has made this change can comment about whether the antenna comes into play.

[jehill]

I was able to successfully update my maps using only a USB key so I still have not seen any downside from not replacing the TCU battery.

[//TMT]

Originally Posted by jehill

I was able to successfully update my maps using only a USB key

My 2020 gets them over the air, or at least it has been as recently as December. I didn't know they could be updated offline. Is there a page for that?

[jehill]

I got my maps from a site called bimmerscene. Google "bimmerscene maps" and you will find it. You need to go into the settings of your nav system to determine what maps are installed. Mine are "North America Way" and I was able to get map updates for 2021-4. Have not found the more recent versions online yet but it varies depending on map type. For example, they just posted "North America Premium" 2023 so if that's what your 2020 M35i uses, you are in luck. If you browse through their forum you can read about requirements for size and format of the USB key you need and other requirements that various BMW models may have.

[chowser51]

Yeah, that's the last map update I could find online as well. 2021-4. I installed it August of 2022. My car did update for my region in 2023.