I just rebuilt the rear axle on my 2014 express van. I started getting errors for my stabilitrack, ABS, traction control, service brake system. Plugged my reader into it and I have cleared the rear speed sensor errors(bad connector) but I am still getting a low brake fluid error. I put in new pads, filled and bled the system, and when I look at the master cylinder, there is a place for a fluid level sensor to hook up, but there are no wires from the harness plugged into it. the brake fluid is topped off correctly. Harness is all original and in good shape. Is the fluid level measured somewhere else on this model?
Thanks in advance.

 

Did you bleed front and back? That warning may be that half of your master cylinder isn't working.

 

yep. Bled the front and the back. I looked up the code number and although the reader says the code is low brake fluid, online, the code is for abs pump circuit open. I ran live data and have 0 volts at the abs pump. I changed fuses and still have the problem so I am about to go through the wiring and check the abs pump.
I still, however , cannot figure out where this van would measure brake fluid.

 

You might find it in here if your parts cross back to a 2006 model year van: https://archive.org/details/isbn_9781418021207
They have some other manuals available too.
It may be worth buying a brief subscription for an online manual to diagnose. The GM factory manuals are silly money.