P0722: Output Shaft Speed Sensor Circuit No Signal

What does P0722 mean?

The output shaft speed sensor (Hall or inductive) reports the speed of the transmission output; it gives the gear ratio together with input speed and on many vehicles also the road speed for speedometer and cruise control. P0722 means the output speed signal is missing while the vehicle is driving. GM's 2025 modules flag under 60 rpm for 3.5–5 s with more than 50 Nm torque and check wheel speeds as well; a 2006 GM table flags no output pulse during 6000 input pulses; Ford under 100–200 rpm for 5–30 s; Saab's Aisin box from 4 km/h. GM rates it after one trip. The transmission goes into limp mode, and speedometer and cruise control may stop working. On GM's 10-speed, P0717 and P0722 together point to the shared sensor supply.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Speedometer reads 0
• Limp mode or fixed gear
• Warning lamp (MIL, transmission)
• Cruise control not working

Common causes

• High Speed sensor faulty (Hall IC or coil open or shorted)
• High Connector or harness corroded, chafed or loose pins (with internal sensors also the pass-through connector)
• Medium Metal debris on the sensor magnet or damaged reluctor wheel
• Low Transmission module or its sensor supply faulty

Likelihood is a general estimate across vehicles; your make and model may differ.