The P0720 trouble code indicates a malfunction in the Output Speed Sensor (OSS) circuit. The OSS is responsible for monitoring the speed of the output shaft of the transmission. This information is used by the engine control module (ECM) or transmission control module (TCM) to determine shift timing and other transmission functions.
P0720 Output Speed Sensor Circuit Malfunction
Code symptoms P0720.
1. Check Engine Light (CEL) illuminated on the dashboard.
2. Harsh or delayed shifting.
3. Transmission slipping or overheating.
4. Erratic speedometer readings or inoperative speedometer.
5. Loss of power or poor acceleration.
6. Vehicle may go into “limp mode” to prevent further damage.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0720.
1. Faulty output speed sensor.
2. Damaged or corroded wiring harness leading to the sensor.
3. Loose or poor electrical connections at the sensor or in the circuit.
4. Malfunctioning ECM or TCM.
5. Short circuit or open circuit in the output speed sensor circuit.
Code Solutions P0720.
1. Inspect the output speed sensor and its wiring harness for any signs of damage, corrosion, or wear. Replace the sensor if it is found to be faulty and repair or replace damaged wiring as necessary.
2. Check for loose or poor electrical connections at the sensor and in the circuit. Ensure that all connections are secure and free of corrosion.
3. Use a multimeter to test the sensor for continuity and proper operation. Replace the sensor if it fails the test.
4. If the sensor and wiring appear to be in good condition, perform a comprehensive diagnosis of the ECM or TCM and related circuits to identify any other potential issues.
5. Clear the trouble codes from the ECM or TCM memory and perform a test drive to see if the issue recurs. If the CEL illuminates again with the same code, further diagnostics may be necessary.
6. If you’re not comfortable performing the diagnostics and repairs yourself, it’s best to seek assistance from a qualified mechanic or dealership. They can use specialized tools and equipment to diagnose the problem accurately and make the necessary repairs.