[wreckman]

Have the exact same problem on my 2012 E93, but it started with only the driver side door-handle dropping out, then a few months later all the rest of the CA system shut down including keyless start.

In my case I suspect it might be that the door-handle module eventually completely broke (or the wire harness broke off to it) and the Comfort Access controller module might decide to shut itself down if it can't detect all its "daughter modules" on the bus. I think I read this in the TIS on CA, at the end it talks about Initialization, but it's a bit vague.

Did you ever get it sorted?

[wreckman]

Actually, I just found this piece of information on another forum which I'll be sure to check on my car at least as it is exactly this symptom I had:

Comfort access problem generally occurs in a BMW. First check the control unit for water damage, you can find control unit right above the battery. It is usually the drivers door handle that brings down the system for the other doors. The small wires sometimes break at the hinge and short out to each other. So check each wire carefully.

So what he means I guess is that the K-CAN bus wires that connect together all the comfort access sub-modules can get shorted and if they get shorted at one place, it brings down all the rest with it.

[wreckman]

Originally Posted by wreckman

So what he means I guess is that the K-CAN bus wires that connect together all the comfort access sub-modules can get shorted and if they get shorted at one place, it brings down all the rest with it.

Yup, problem solved - I disconnected the driver's side handle, and everything started working again (both the ELV and the car started up nicely).. so a short or similar inside the handle. It causes the BUS_PA one-wire bus system to fail, and that is the same bus that controls the ELV.

And the shop wanted to change out the steering column...

This should be something every BMW shop should know about (that the comfort access handles can bring down the entire car).