Ford
Type:
    Powertrain - Transmission - ISO/SAE Controlled
Description:
    OSS Sensor No Signal Conditions
Cause:
    Engine running, then the PCM did not detect any OSS signals upon initial vehicle movement

Generic
Type:
    Powertrain - Transmission - ISO/SAE Controlled
Description:
    Output Speed Sensor Circuit No Signal

GM
Type:
    Powertrain - Transmission - ISO/SAE Controlled
Description:
    Vehicle Speed Sensor Circuit Low Input Conditions
Cause:
    Engine running, starting from a complete stop, turbine speed over 1400 rpm, steady moderate throttle, speed ratio across the torque converter over 700 rpm, then in a 1 -2 upshift the PCM detected the turbine speed pulled-down by a 1-2 ratio with no VSS input.