Get your own code scanner. If you look up the code you find
The Vehicle Speed Sensor (VSS) assembly provides vehicle speed information to the Powertrain Control Module (PCM). The VSS assembly is a Permanent Magnet (PM) generator. The PM generator produces a pulsing AC voltage as rotor teeth on the transmission output shaft pass through the sensor's magnetic field. The AC voltage level and the number of pulses increase as the speed of the vehicle increases. The PCM converts the pulsing voltage to vehicle speed. The PCM uses the vehicle speed signal to determine shift timing and torque converter clutch (TCC) scheduling.
P0502 CHEVROLET Vehicle Speed Sensor Circuit Low Input | AutoCodes

I would start checking ground connections to make sure nothing was messed up when you started disabling chimes as per your other posts. A bad ground can ruin your day. I would also just consider replacing the speed sensor.