P0722

Output Speed Sensor No Signal

P0722 is a generic OBD-II powertrain diagnostic trouble code: Output Speed Sensor No Signal. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.

Code
P0722
Group
Powertrain
System
Powertrain
Severity
high
Need P0722 disabled?
RaceTune permanently disables any OBD-II trouble code on supported ECUs — for motorsport, off-road, and export use.
→

What P0722 means

P0722 is stored when the TCM or PCM detects no signal from the transmission output shaft speed (OSS) sensor under operating conditions where a signal is expected. The output speed sensor monitors the rotational speed of the transmission's output shaft, which is mechanically linked to the driveshaft and ultimately to the driven wheels. This signal is one of the primary inputs the TCM uses to calculate vehicle speed, determine actual gear ratios, manage torque converter clutch (TCC) engagement, and coordinate shift scheduling with engine load and throttle inputs.

The output speed sensor is most commonly a Hall-effect or variable-reluctance sensor mounted on the transmission tailshaft housing or inside the transmission near the output shaft tone wheel. On many modern vehicles the output speed sensor signal is also shared with the instrument cluster for vehicle speed display and with the ABS/stability control module — meaning a failed OSS can affect multiple vehicle systems simultaneously. When the TCM sees no output signal while the input shaft is spinning, it recognises a fault condition and stores P0722; on most platforms this triggers limp-home mode immediately.

Wiring faults are among the most common causes: the sensor harness at the tailshaft area is exposed to road debris, moisture, and vibration, making it vulnerable to chafing and connector corrosion. The sensor itself is also exposed externally on many rear-wheel-drive and four-wheel-drive transmissions, making it susceptible to physical damage from road impacts. Internal transmission debris on the sensor tip is another frequent contributor, particularly on higher-mileage units with worn bearings or bushings shedding metal particles.

Because the output speed signal underpins both transmission control and vehicle speed calculation, P0722 is treated as a high-severity fault. Related codes such as P0500 (Vehicle Speed Sensor malfunction) and P0720 (OSS circuit malfunction) may appear alongside it and should be addressed together to confirm the true root cause before replacing components.

Common causes

Most-frequently reported root causes when P0722 is logged.

  • 1
    Faulty or failed output shaft speed sensor
  • 2
    Open circuit or short in the OSS wiring harness or connector
  • 3
    Corroded, damaged, or moisture-contaminated sensor connector
  • 4
    Physical damage to the sensor from road debris or impact
  • 5
    Metal debris on the sensor tip from internal transmission wear
  • 6
    Damaged or missing tone wheel teeth on the output shaft
  • 7
    Low or degraded ATF compromising sensor signal strength
  • 8
    Faulty TCM failing to process the sensor signal
  • 9
    Aftermarket lift or driveline modifications causing sensor misalignment

Symptoms drivers notice

Check Engine Light and/or Transmission Warning Light illuminated
Transmission enters limp mode or refuses to shift
Speedometer reading at zero or erratic while vehicle is moving
ABS and traction/stability control warning lights illuminated
Harsh, delayed, or absent upshifts and downshifts
Torque converter clutch not engaging
Cruise control inoperative

How to diagnose P0722

A typical diagnostic flow when this code is present.

  1. 1
    Scan all modules (not just the PCM/TCM) for DTCs — P0722 can trigger ABS and instrument cluster codes; note every code before clearing
  2. 2
    Check live OSS PID data on a scan tool while someone slowly rolls the vehicle forward; the sensor should show a speed reading proportional to wheel movement
  3. 3
    Locate the output speed sensor on the transmission tailshaft housing; visually inspect for physical damage, cracks, and connector condition
  4. 4
    Measure sensor resistance (VR type) or supply/signal voltage (Hall type) directly at the sensor connector and compare to specification
  5. 5
    Inspect the harness from the sensor back to the TCM for chafing, cuts, moisture ingress, or contact with driveline components
  6. 6
    Remove the sensor and inspect the tip and tone wheel for metal debris or tooth damage; clean the sensor tip before reinstalling or replacing
  7. 7
    Replace the sensor if out of specification or visibly damaged; clear codes and verify OSS live data shows a clean signal across a full speed range before road-testing
  8. 8
    If the fault persists with a new sensor and verified wiring, drain the ATF and inspect for heavy metallic contamination suggesting internal mechanical damage

Related powertrain codes

Frequently asked questions

Why does P0722 also cause my ABS light to come on?

On many vehicles the output speed sensor signal is shared with the ABS/stability control module to provide vehicle speed reference. When the signal is lost, the ABS module cannot confirm wheel speed and disables ABS and traction control as a safety precaution.

Can P0722 cause my speedometer to stop working?

Yes. If the instrument cluster receives vehicle speed from the transmission output speed sensor (directly or via the PCM/CAN bus), losing that signal will cause the speedometer to read zero or behave erratically.

What is the difference between P0720 and P0722?

P0720 indicates a general output speed sensor circuit malfunction — the signal is present but erratic or out of range. P0722 specifically means no signal is detected at all. P0722 is typically a harder fault: complete sensor failure, broken wire, or disconnected connector.

Is P0722 dangerous to drive with?

Driving with P0722 active is risky. Limp mode limits transmission function, ABS may be disabled, and the speedometer may be non-functional. You should drive only as necessary to reach a repair facility and avoid highway speeds.

Disabling P0722 in software

RaceTune can permanently disable P0722 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.

Permanent
The monitor is disabled in the ECU itself — not just cleared. It cannot return.
Tailored to your file
Each patch is matched to your specific software version — never a one-size-fits-all file.
Reversible
The original file is always preserved. Reflash the stock to return the ECU to factory state.

Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.

Got P0722 in your scan?

Upload your ECU file — we'll identify the exact software version and confirm whether a disable is available for your car.

Upload your file