OBD codes / P0722
P0722
SeriousOutput Speed Sensor Circuit No Signal
Take P0722 seriously before driving far: on many cars you'll have no working speedometer, and the transmission may be in limp mode or shifting erratically. A careful, short drive to the shop is reasonable; a highway commute with no speedometer and unpredictable shifts is not.
What this code means
P0722 means the computer is receiving no signal at all from the output speed sensor — as far as the transmission knows, the car is standing still even while driving. That's a more decisive fault than P0721's erratic signal, and it points to a dead sensor, broken wiring, an unplugged connector, or a damaged tone ring. The consequences are usually immediate: the speedometer reads zero on many vehicles, cruise control won't work, shifts become erratic or the transmission drops into limp mode, since the computer can't confirm any gear ratio without knowing output speed. A hard, constant failure like this is typically quick to diagnose with basic circuit testing, and on most transmissions the sensor is externally mounted and inexpensive to replace.
Symptoms you might notice
- Speedometer stuck at zero while driving
- Cruise control inoperative
- Harsh or erratic shifting, or limp mode
- Delayed or absent upshifts
- Check-engine light
What it costs to fix
Typical range: $60–$450 · about ~0.3–1.5 hrs of labor
| If the cause is… | Part | Labor |
|---|---|---|
| Output speed sensor | $30–$150 | ~0.3–1 hrs |
| Wiring / connector repair | $10–$120 | ~0.5–1.5 hrs |
Most output speed sensors bolt into the tailhousing or case externally — a fast, cheap replacement. Internal designs and tone-ring damage push the cost up, but those are the minority outcome for this code.
The price swings on which cause it turns out to be — so confirm the cause before paying. Diagnose P0722 for my exact vehicle →
Frequently asked
Why did my speedometer die along with this code?
Because on many vehicles the speedometer is driven by the output speed sensor's signal. No signal, no reading. Replacing the sensor (or fixing its wiring) typically brings the speedometer, cruise control, and normal shifting back together.
Is P0722 the sensor or something worse?
The odds strongly favor the sensor or its wiring — cheap, accessible fixes on most vehicles. The rare worse case is a damaged tone ring inside the transmission. A technician can usually distinguish them by testing the circuit and inspecting the sensor before any big commitments.
Why does the transmission shift badly without this sensor?
Output speed is half of the gear-ratio equation the computer checks constantly. Without it, the computer can't confirm what gear it's actually in, so it guesses conservatively — harsh shifts, held gears, or full limp mode to protect the hardware.
Should the fluid be checked too?
Yes, first. It's free, and if the fluid is low, burnt, or full of glitter, that's evidence of a bigger story than a sensor. Heavy debris on a magnetic sensor tip can even be what killed the signal.
Seeing P0722 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0722 for my vehicleRelated trouble codes
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Generic OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.