What else could the problem be?

What is your question?

I have a 2003 trailblazer LTZ, just bought month ago, had misfire repaired, then all of a sudden while passing a truck on road, ABS light, E-break light, comes on, she sticks in first gear, and speedo and odometer stopps working, i have check codes multiple times and clearing them after replacing the 3 speed sensore on the transmission because i couldnt figure out which one was the VSS, as the code was "REAR SPEED SIGINAL MISSING" but still code, then i replaced ECBM after replacing the plug and rewiring ,what i think is the VSS using a 18 guage wire and again clearing the codes every time, but still no change, but now i can hear a humming siginal coming only when TB is moving and louder as speed increases, can someone help me figure this out?

How long has your 2003 Chevrolet Trailblazer had this problem?

A few weeks after she came out of shop from having misfire in chamber 1 fixed