2001 Chevy Impala Security Message on; Door and trunk locks

Among other problems, I took my Impala in to check why the security light was going on regularly. They said likely BCM but that it was an erroneous signal and recommended I just ignore it. So I let it go; 5 days later my door and trunk locks don't work - except with the key and manually pushing the locks on the doors. I talked to the dealer where I had it fixed but they are not sure it's the same problem unless I pay for a new diagnostic. Should I just let this go? It's inconvenient but I can sure live with locks not being automatic. Am I at risk of a breakdown? Anything I can fix myself? Your thoughts? I've been laid off, and the other stuff I had fixed came to $1300. However, I also can't afford to be stranded.