Code u2100 this was the code that came up

You have a CAN-BUS communication malfunction. In other words probably a broken wire, bad connection.

Great. Now fix the right front wheel sensor c0040, coo73. Next the u2100 is a voltage issue. The DTC did not see enough voltage to the system. Check the battery and connections. Check charging system.

Your 1087 code is a faulty door module, which is part of the reason your mirror isnt working right..and the 11f7 code means your mirror needs resynced from being moved manually.

It refers to a problem in the electronic communication network the car has, called the "can-bus".

U2100 - CAN-BUS Communication Malfunction.(GM cars).
You'll need to see if there are any other codes as this one is a very general code. Take it to a good auto electrician and they should be able to trace the fault more accurately.

in my car Vauxhall zafira this cod comes up which is u2100c and can u please tell me how to fix the problem , I change the car key battery . still the light is there.

U2100 has to do with restraint control module. It should all be under warranty

Here's code P0443.Here's code P1682.Here's code U2100.

U codes are network codes - issues with communication between modules. Start there, as these can cause funky things to happen and can set P codes, as well. Once the U code is resolved, clear them all and see if they come back.

U2100:
"Key on and the TCM (transmission control module) detected a loss of communication on either Communication Area Network (CAN) Bus line for one second"

well a U code like U2100 is a communication error,meaning there is a bad computer in the car or a wires issue,one of the other computer in the car can not talk to the other so its send a loss of communication code as you got,,,,i would highly rec you go to the dealer for this concern