e90 Steering Wheels Control Buttons

[downunderbmer]

The steering wheel buttons on my 2007 E90 do not work and do not light up when the running lights are on either. The horn works fine. I tried replacing the slip ring/clock spring to no avail.
I would like to test the buttons themselves but I see no obvious way to remove them from the steering wheel. There are no screws holding the buttons in place. Should I just pry them loose using a flat head screwdriver? (photo 3)
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[JDStrickland]

I would not expect that all 6 buttons (4 discreet and 2 rockers -- totaling 8 switches) would all fail unless there was a common point of connection among all of them. Without a schematic, it's impossible to say where to go next, but I seriously doubt that you will have trouble with the switches.

They can be designed such that there is power distributed to all of them, and the power is sent to a controller with pull-up resistors that in turn operate a transistor, in this instance, look for a blown fuse that causes the power to not be present.

They can also be designed with ground distributed to all of them, and then power is pulled down to activate a transistor to invoke the operation of the switch. In this case, you would have a bad control module.

[downunderbmer]

I would not expect that all 6 buttons (4 discreet and 2 rockers -- totaling 8 switches) would all fail unless there was a common point of connection among all of them. Without a schematic, it's impossible to say where to go next, but I seriously doubt that you will have trouble with the switches.

They can be designed such that there is power distributed to all of them, and the power is sent to a controller with pull-up resistors that in turn operate a transistor, in this instance, look for a blown fuse that causes the power to not be present.
They can also be designed with ground distributed to all of them, and then power is pulled down to activate a transistor to invoke the operation of the switch. In this case, you would have a bad control module.

As you will tell from the question, I am no auto electrician.
There are wires from both the right and left switch cluster modules which then terminate in a plastic connector with 6 or 8 pins. Is it possible to somehow test to see if there is a break in a wire or something similar using a meter with a probe?

[JDStrickland]

As you will tell from the question, I am no auto electrician.
There are wires from both the right and left switch cluster modules which then terminate in a plastic connector with 6 or 8 pins. Is it possible to somehow test to see if there is a break in a wire or something similar using a meter with a probe?

You don't need to take the switches (buttons) out, but you need to know which of the connector pins is the one that is common to all of the switches, then you can work through to see if the switches work.

Frankly, it is my opinion that you have a blown fuse OR a failed controller that is causing the data buss to be flaky. The wires from the connector to the switches are pretty well protected, I would expect your trouble is on the vehicle side of that connection, not the steering wheel side.