The diagnostic code P0720 OBD2 indicates that there is a problem in the OSS (Output Shaft Speed Sensor) circuit. The PCM (Powertrain Control Module) takes the signal from the OSS (Output shaft speed) sensor. Thus, it determines the best way to make changes, this information is sent to the transmission. In case the Powertrain Control Module (PCM) does not receive information from the OSS sensor or this information is received sporadically or with errors, the DTC code P0720 is set.