Fix code P0720 Output Speed Sensor Circuit Malfunction
If the output speed sensor doesn’t work properly, it’ll set a P0720 Output Speed Sensor Circuit Malfunction code.The output speed sensor on the transmission tells the computer how well the transmission converted the input torque to output RPMs. If the output doesn’t correlate to the input torque, engine RPM, and road speed, the computer assumes there’s a problem internal to the transmission. Rather than allow the transmission to tear itself up, it can put the transmission into limited operation.
The output speed sensor normally puts out an AC current. To read it, you’ll need an automotive scope. But these sensor may read just fine on a scope and still fail due to high internal resistance. So, instead of wasting your time with the recommended scope test, simply test for resistance. Disconnect the electrical connector from the sensor and check for less than 800 ohms. If your reading exceeds 800, replace the sensor.
© 2012 Rick Muscoplat