P0722 code: Output Speed Sensor Circuit No Signal
P0722 means output Speed Sensor Circuit No Signal. The code says where to look, not what failed — the fix depends on which cause your car actually has.
What P0722 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.
P0722 symptoms
- 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 P0722
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 →
How to fix P0722
Easy — basic tools, most owners can do this
- Rule out fluid quickly, then focus on the circuit
A completely dead output signal is almost never caused by fluid alone, though a sensor packed in metallic sludge can be. Check the level by the correct procedure and look at the condition; if the fluid is clean and full, spend your time on the electrical side, where most P0722 faults live.
- Check the connector at the tail of the transmission
The output sensor sits low and toward the rear, where road spray, salt, and recent driveshaft or exhaust work can unplug or corrode it. Look for a connector hanging free, a broken lock tab, or green corrosion in the terminals, and ask whether anyone has had the driveshaft, axle, or exhaust off lately.
- Bench-test the sensor's output
Remove a two-wire magnetic sensor, set a meter to AC millivolts across its pins, and pass a steel screwdriver quickly by the tip; a working sensor produces a small pulse each time. A coil that reads open on the ohms scale, or produces nothing, is dead. Hall-type sensors need power to test, so check their reference and ground at the harness instead.
- Trace the signal path, including shared branches
On some vehicles the output-speed signal also feeds the instrument cluster or other modules, so a short in any branch can pull the signal down everywhere. Check continuity from the sensor connector to the module and to ground, and if the speedometer is dead too, unplug the other modules on that circuit one at a time to see if the signal returns.
- Fit the new sensor and look at the tone ring
Before installing a replacement, shine a light or slip a borescope into the sensor bore to check the reluctor teeth for damage or missing sections. If they look intact, fit the sensor with a new O-ring, clear the codes, and confirm the speedometer and shifting return to normal on a short test drive.
DIY or shop? For most owners P0722 is a realistic driveway repair: the sensor is commonly mounted outside the case, the bench and continuity tests need nothing more than a multimeter, and replacement takes minutes. The job moves to a shop when the sensor is internal, when the reluctor ring is damaged and the transmission must be opened, or when a shorted branch of a shared speed signal means tracing wiring behind the dash. With no speedometer and erratic shifts, tow it rather than commute on it.
Tools for the DIY steps: Digital multimeter with AC millivolt range · Socket set · Flashlight or borescope · New sensor O-ring · Wiring diagram
Not sure which step applies to your car? Get the likely cause for your exact vehicle before buying anything for P0722.
Start a case with P0722 and your car. Redline weighs these causes against what your car shows, and names the check that would settle it before you buy parts.
Can I drive with P0722?
Redline can’t determine from a symptom or code alone whether your car is safe to drive.
P0722: common questions
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?
Check it 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.
Related trouble codes
Don’t have a scanner yet? A ~$25 Bluetooth adapter reads codes like P0722 from your phone. See our guide to the best OBD2 Bluetooth adapters. Run a repair shop? See Redline for shops.
Generic OBD-II reference. Manufacturer-specific behavior varies. Confirm with a scan tool and, for safety-related codes, a professional inspection. Cost ranges are reference ranges, not quotes.
Seeing P0722 on your car?
Every problem becomes a Case. Tell Redline what the car is doing: it shows what the evidence supports, what’s still missing, and what to check next, before you approve a repair.
“Inner pad ~1 mm. Outer pad 3 mm.”
Next: check the slide pins move freely before buying parts.