I have a 2011 Silverado 2500HD. I'm getting C0131-01 specifically with different OBD2 readers. It will not clear. The DIC also says service stabilitrack and service trailer brake system.
There's not a whole lot of info about fixing it and it seems what info I can find says different things.
Some sites say it is the Electronic Brake Control Module, some say it is the Brake Pressure Switch.
Oreillys and Autozone have a brake pressure sensor that fits the model truck i have. For the life of me I can't find it on my truck anywhere and every diagram I've looked at has it under the hood close to the master cylinder.
But I've also read that its built into the abs module.
Can anyone help me? I've lost sleep over this one.

This is the part in question that is supposedly shorted out.

 

If you have JL4, its part of the brake pressure modulator valve. With out JL4 it's in the aluminum part of the master cylinder opposite side of the brake lines (right side).

 

How do i ensure its JL4? Which I'm 90% positive it is.

 

JL4 is the RPO code for the brake option. Have to look on your build sheet. Or is there a sensor on the right (side facing the engine) of the aluminum body of the master cylinder. If there is not then you have JL4, and to test this system. SI doc #2138519.
Apply and release the brake pedal. Verify the brake lights operate properly, If not diag the brake lights.
If they operate properly, Replace the brake pressure modulator valve (BPMV) and verify the code doen't reset.
If the code resets replace the EBCM (electronic brake control module)