Identify this rear sensor?

[Scurrah]

Does anyone know what this sensor is? It's mounted to the rear of the car between the bumper (or trailer hitch frame) and the car. It's a 2014 xDrive35i. Is it safe to mount something right close to it? Like a hitch wiring harness?

[r33_RGSport]

Originally Posted by Scurrah

Does anyone know what this sensor is? It's mounted to the rear of the car between the bumper (or trailer hitch frame) and the car. It's a 2014 xDrive35i. Is it safe to mount something right close to it? Like a hitch wiring harness?

That's your comfort access sensor to detect your key to allow you to open the trunk.

That is safe to mount that hitch close by. Just don't get any wires cut.

[Scurrah]

Thank you!!!!

[Barbera335]

Originally Posted by r33_RGSport

That's your comfort access sensor to detect your key to allow you to open the trunk.

That is safe to mount that hitch close by. Just don't get any wires cut.

More accurately, it is a comfort access trigger. It does not detect the key. When you initiate the process by pressing the trunk release button this comfort access trigger sends out a command which wakes up all nearby keys. The keys then transmit their identifying signal back to the vehicle. This signal is picked up by the diversity antennae in the rear window and then is relayed to the BDC control unit which then processes the signal and executes the unlock request.

[r33_RGSport]

Originally Posted by Barbera335

More accurately, it is a comfort access trigger. It does not detect the key. When you initiate the process by pressing the trunk release button this comfort access trigger sends out a command which wakes up all nearby keys. The keys then transmit their identifying signal back to the vehicle. This signal is picked up by the diversity antennae in the rear window and then is relayed to the BDC control unit which then processes the signal and executes the unlock request.

Wow, even much more clearer.
Thank you.

[motex]

Originally Posted by Barbera335

More accurately, it is a comfort access trigger. It does not detect the key. When you initiate the process by pressing the trunk release button this comfort access trigger sends out a command which wakes up all nearby keys. The keys then transmit their identifying signal back to the vehicle. This signal is picked up by the diversity antennae in the rear window and then is relayed to the BDC control unit which then processes the signal and executes the unlock request.

I recall in my former M4 just slide my foot under the rear bumper for a couple of seconds and then the trunk just open itself, no need to touch anything else, I understand that the main idea of the comfort access is to open the trunk "wirelessly" (if you can call it that way..) when both hands are busy?
I haven't try this on my F15 yet, will do some testing later on

[r33_RGSport]

Originally Posted by motex

I recall in my former M4 just slide my foot under the rear bumper for a couple of seconds and then the trunk just open itself, no need to touch anything else, I understand that the main idea of the comfort access is to open the trunk "wirelessly" (if you can call it that way..) when both hands are busy?
I haven't try this on my F15 yet, will do some testing later on

That feature is not available on the F15 unfortunately. I been trying to retrofit it, but didn't have time or diagram needed to do the retrofit.
My guess, it is not available on the F15 since the sensor will be blocked when you have a tow hitch installed.

[motex]

I will ask my dealer and post my findings

[42pilot]

Originally Posted by Barbera335

More accurately, it is a comfort access trigger. It does not detect the key. When you initiate the process by pressing the trunk release button this comfort access trigger sends out a command which wakes up all nearby keys. The keys then transmit their identifying signal back to the vehicle. This signal is picked up by the diversity antennae in the rear window and then is relayed to the BDC control unit which then processes the signal and executes the unlock request.

Wholly crap.

[42pilot]

Originally Posted by Barbera335

More accurately, it is a comfort access trigger. It does not detect the key. When you initiate the process by pressing the trunk release button this comfort access trigger sends out a command which wakes up all nearby keys. The keys then transmit their identifying signal back to the vehicle. This signal is picked up by the diversity antennae in the rear window and then is relayed to the BDC control unit which then processes the signal and executes the unlock request.

And a great explanation of the process. Thank you

[Scurrah]

Pretty cool process too!

That's the Invisihitch that I just installed myself (scary as hell pulling that bumper cover off). It puts the 7-way wiring harness tight in between the hitch frame and that sensor/trigger. Seems too tight to me. But they're positive that it can go there. I was worried it was some kind of crash sensor that would going to blow my airbags if I ever slammed on the brakes while towing a big boat. Looks like I'm safe.

[Kessler35is]

Originally Posted by Scurrah

Pretty cool process too!

That's the Invisihitch that I just installed myself (scary as hell pulling that bumper cover off). It puts the 7-way wiring harness tight in between the hitch frame and that sensor/trigger. Seems too tight to me. But they're positive that it can go there. I was worried it was some kind of crash sensor that would going to blow my airbags if I ever slammed on the brakes while towing a big boat. Looks like I'm safe.

Airbag sensors are normally mounted in a central part of the auto, I have seen them mounted under the center console many times in vehicles.

This is the best spot so they can read all of the G-Force loads, also any X, Y, or Z axis movements of the vehicle. With this info the computer can determine if and which of the air bags to be set off will be of use or harm. The old days of just getting in a small bumper dent and getting a free facial reconstruction should be over.