P0720 — Output Speed Sensor Circuit
Moderate severityWhat it means
P0720 is stored when the engine control unit sees a fault involving the output speed sensor circuit. The output speed sensor measures the transmission's output shaft speed (vehicle speed); the control unit uses it for shift timing and the speedometer. The control unit has flagged this circuit or signal as outside its normal operating range.
Common symptoms
- Speedometer dead or erratic
- Harsh or wrong-timed shifts
- Limp mode in some cases
Likely causes
- A wiring, connector or ground problem in the circuit
- A failed sensor or actuator in the circuit
- Faulty output speed sensor
- Wiring/connector fault at the transmission
What to check first
- Inspect the connector and wiring for damage, corrosion or loose pins
- Compare output speed in live data with actual/GPS speed
- Inspect the sensor connector and wiring
Can you keep driving?
Drivable with care, but shifting and the speedometer may misbehave; diagnose soon.
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