P0720: Output speed sensor circuit

How to read it

P0720 is one of the standard OBD-II trouble codes stored when the check engine light comes on. A generic list of OBD-II codes names it “Output Speed Sensor Circuit”; an Infiniti service bulletin calls it “OUTPUT SPEED SENSOR”.

Also searched as: code P0720, P0720 code.

What the monitor checks

The federal rule’s catch-all covers any other electronic powertrain component that sends input to or takes commands from the on-board computer and has a measurable effect on emissions.

Look-alikes

In the same list, the next code, P0721, is “Output Speed Sensor Circuit Range/Performance”.

What the manual says to do

Ford’s F-150 manual says that if the indicator stays on, the vehicle should be serviced at the first available opportunity, and that continued driving with it on can mean higher emissions, lower fuel economy, rougher running and more costly repairs.

How the light goes out

Under the federal rule, the check engine light may go out once the fault has not come back during three trips in a row in which its monitor runs without finding it. The system may erase the stored code if the same code has not been registered again in at least 40 engine warm-up cycles.