ABS faults 2006 Colorado troubleshooting

Hey guys, I’m in desperate need of some help on my ‘06 Colorado 4WD. First I’ll say the ABS light has been on since we acquired the truck a few months ago, being told that they “never had issues, so just let it be”. About a month ago, the driver front brakes start to squeal and had that drag sound as if the rotor was uneven or bent. It eventually was so bad that I decided to take care of it. So I went and bought a new rotor and pads for both front brakes, and my husband and his buddy put them on. Afterwards, we still had a problem so his buddy brought over a code reader. He got codes for ABS for the wheel speed sensor. Come to find out that someone broke off the wire on driver side when putting everything back together. So I went and bought 2 new hub assembly’s with sensors and put them on myself. Then I bought a scanner and came back with C0220 and C0040. Now, I’m pretty good with working on vehicles, having been doing it since I was 14, so 29 years. I have a multimeter, and I can do basic troubleshooting. But when it comes to tracing the wires and finding out where the break is to cause no communication with the EBCM, I’m having difficulty. I need a sure fire way to figure this out ASAP to get back on the road. Should I start at the ecbm? Any help appreciated! Oh and what exactly does “channel in release too long” mean?