DTC P0720: Output Shaft (Countershaft) Speed Sensor Circuit Malfunction: General Description

The output shaft (countershaft) speed sensor is attached to the transmission housing to sense output shaft (countershaft) revolutions. The engine control module (ECM) determines the vehicle speed according to the signal from the output shaft (countershaft) speed sensor to the control units. If no signal from the output shaft (countershaft) speed sensor is received for a set time, the ECM detects a malfunction and a DTC is stored.