The on-board diagnostics system (OBD), which is installed in your vehicle, detects and saves 5-character fault codes to its memory. This allows you to identify possible faults in the vehicle and their causes. When the powertrain control or transmission control modules detect a fault with the output shaft sensor (OSS) circuit or the sensor itself, they trigger the P0720 code. The powertrain control module receives data from several sensors. The speed sensor, or transmission speed sensors, is one of the sensors located in your vehicle’s transmission. Two of these sensors are found in every car: the output shaft sensor (OSS) and the input shaft sensor (ISS). The input shaft sensor measures the rotational speeds of the torque converter/input sleeve. The sensor detects internal transmission revolutions and sends data to the PCM.
The output shaft sensor measures the rotational speed on the output shaft of the transmission. This sensor provides accurate and real-time readings of speed and distance on the speedometer. The PCM uses the voltage signal of the output shaft sensor to determine the proper gearshift strategy. This information is then sent to the transmission. The PCM sets the P0720 code if it cannot receive the signal from the sensor, or if the signal is slow, irregular or constant.
This code is the similiar to P0721, P0722 and P0723.
Table of Contents
What are the possible causes of fault code P0720?
- Faulty output shaft speed sensor
- Faulty input shaft speed sensor
- Cables that are damaged or worn out or connectors that have come loose
- Transmission oil contaminated or low
- Defective engine drivability sensor
- Faulty Gear Shift Solenoids
- Faulty temperature sensor for transmission oil
- PCM fault (rarely)
Note: On some vehicles, the OSS is aligned to the transmission oil temp (TFT). The OSS sensor can malfunction if the TFT sensor is faulty or if the cables are damaged.
What are the symptoms of fault code P0720?
- Engine fault lamp illuminated
- Delayed shift in gear
- Faulty speed (km/h) indicator
- Misfiring engine
- Fuel consumption increases
How to Fix Error Code P0720?
- Replace the output shaft speed sensors
- Replace the input shaft speed sensors
- Replace damaged connectors or cables
- Filling up the transmission fluid
- Replace the transmission fluid temperature sensors
- Replace the transmission filter
- Repairing transmission leaks
- Replacement of the PCM
A technician should examine the cause of the damage caused to the output sensor or other components after the faulty component has been replaced. If, for example, an engine leak causes a sensor to fail, the leak as well as the sensor must be repaired.
How Serious Is the P0720 Fault Code?
The P0720 code does not make a vehicle undriveable. If the fault is not fixed promptly and ignored, it may worsen, and cause transmission damage.
