Blind spot message code b18b6?

Commonly that is a bad radar unit but we need to test to ensure it isn't a wiring fault. First, clear the code, power off, power back on, does the code return? Yes = go to the radar unit behind the rear bumper cover and unplug the 6 pin connector. Check that with the ignition on you have battery voltage at pins 2 & 5 Got power? Yes = unplug the 16 pin connector from the blind spot control module (Inside the trunk, left side behind the trim panel) and check for continuity on the CAN lines, Pin 2 on the 16 to pin 1 on the 6 pin AND Pin 3 on the 16 pin to pin 3 on the 6 pin. Got continuity, replace the radar unit and use the ADAS targets to check the aim of the replacement part.
If you don't have power or continuity look at the plugs and wiring for damage.

So the radar if bad needs to be calibrated as far as aim? same for the Blind spot module?

Yes, if the radar unit behind the bumper is bad you will need to calibrate it's replacement. Most of the modern scan tools can do that, you just need to have a target set up correctly. You can make a target stand out of pvc pipe and a flat chunk of metal for the target. The "angle gauge" Honda 07AAJ-STKA170 is actually a small squared off block with a laser pointer on top in a groove. You put it on the face of the radar sensor and aim it at the target Honda 07AAJ-STKA160 if the laser hits correctly you are done. You then use the scan tool to erase the code(s) and ship the car out. I've done a couple and pretty much it was simple, as long as the vehicle hadn't been hit the mounting is clean and rust free they lined up with just bolting them in place.

Number 4 has power, number 1 is ground

Continuity is between 3 on the 16 connector and 2 on the 6 connector

Also continuity on pin 2 on 16 connector and pin 3 on 6 connector

OK, you pulled the connector on the module, not the inline 6 pin connection, but you have powers and ground and the data lines, so the radar module behind the bumper is bad (common failure). Swap it with a replacement and verify that it detects a target (or swap it, make sure the code clears and move a second vehicle into the blind spot and see if it detects it) Put the cover back on and verify it again and you should be done.

The most nline is in first video. The inline is the one that connects to the radar. The 16 one connects to module

There is a short harness that plugs into the module with the second 6 pin farther up. But it doesn't really matter as the test shows that the wires are OK and that you have power and ground as well as the data lines. Unfortunately there isn't a reliable way to test the module without either a second vehicle that you could swap it with or the test gear used in production to check it's operation. If you have a scope you might be able to connect to the data lines and see if it is communicating with the control module, but that wouldn't tell you if it's actually the correct data. Just another fun thing with ADAS components.

Unfortunately, even with the radar replacement same exact message, it won't even delete before I start the car.

That is not a common thing, usually it's the radar unit causing the problem. It could be a bad control module but I don't recall ever replacing one for that error. Especially when the wiring checks out. Where did the part come from? New or salvage? Does the error show as current, history or permanent? The last one cannot be removed until the vehicle itself runs the test cycles a number of times.

Used. With a bad control unit i would think both sides wont work. With autel does not give permanent or history like the smaller ones. If this was an engine code i would be able tosee if its permanent but it wont clear at all

The control unit uses different signals for each side so it's possible it has a problem if the original one shorted and caused a problem in the module. I'm not sure if you could swap signals from one side to the other, in theory it might work. Basically go to the control module and swap the left side data to the right side, get a right side error, the replacement sensor is bad, still have the left side error, the control module got damaged. Never tried it on that brand but it works with many other types of sensors.

I gave up and removed the other side so code is now not there so this used one hopefully just bad. am returning and getting another unless they need coding but I doubt

Sounds like a plan. The control module has to be activated if it's swapped but that is something you do through the BCM, it pretty much just gets reset. The radar themselves are plug and play. Just may need to be aimed properly.

I ordered another radar. I also noticed the mirror itself was glued not sure if it has anything to do with this issue

I wouldn't think the mirror was involved as the system uses just the two radar sensors and the control module.