The meter reminded that this “emergency assistance is not available” and checked the forum information. Most of it was caused by the failure of the sos battery itself. So I bought batteries through the “curator” in the 3 series group. Thanks also for telling you the detailed location diagram of this small battery. Thinking that changing this would not be a matter of minutes, I overestimated myself. It takes about 2 hours from the beginning to the end, and it takes a lot of time to work hard on the waist and neck.
This is the original way. To remove this cover plate, you need to use a special interior pry plate. It doesn’t cost much to buy one. Save time and effort.
For the removed cover plate, pay attention to the clip in the red area that can be pried off directly. Pay special attention to the green arrow. It is a hook inside. You need to extend the crowbar inside and push the hook inward. The hook will disengage, and the cover plate will come off. Don’t force it.
After dismantling, the roll of black wire was ignored by the extra wire in the driving recorder behind me.
There is a clip at each red arrow that needs to be pried open with a plastic crowbar. After prying open it, it’s time to show the strength of your waist. You understand everything you know. Of course, in order to find this module at this time, my neck was also very uncomfortable.
Stretch your neck behind the headrest until you see the white box.
Do you see the gap? Within the range of vision you can see, gently pull open the roof. Be careful not to use force at this time. Put your hand into the roof of the car, find the gap shown in the picture above, and bend it down and the module will fall.
As shown in the figure: the red arrow on the left and the red arrow on the right have a plug each. The entire plug cannot be seen due to line of sight problems. Never pull the plug by force. The left one must be pinched on both sides to easily pull it out. There is a small clip above the plug on the right. You must hold down the small clip before you can pull it out.
At this time, the module has been removed by me, and the original old battery is at the red arrow. Remove it and replace it with a new battery.
Compare the new battery (left) and the old battery (right) to determine the original quality
Remember these three red arrows. You also need some skills when installing. The white module needs to be pushed to the front and pulled back to get stuck.
While it is stuck, push down the switch at the red arrow and hear a clear “click” to prove that it is installed in place.
back to normal
Finally, will changing this SOS cause such creases on the roof? Will it get better after a long time?
Last picture: My hand is worn out. Remind everyone to wear thinner gloves if you change it yourself.
PayneMacAdam 
7 
September 4, 2024 
