Output Speed Sensor Range/Performance
Your transmission's speedometer sensor isn't sending reliable signals to the engine computer, like a car speedometer needle that bounces erratically. This prevents the transmission from shifting smoothly because it can't accurately track vehicle speed.
The ECM monitors output shaft speed from the transmission speed sensor to determine when to shift gears and engage the torque converter lockup. It compares sensor frequency against expected values based on input speed and gear selection, flagging faults when readings fall outside normal operating range or show erratic patterns.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Output Speed Sensor Frequency | Proportional to vehicle speed (0-8000+ Hz depending on transmission) | Signal missing, erratic, or drops below minimum expected for current gear |
| Sensor Signal Voltage | 0.2V to 4.8V (depending on sensor type) | Stuck high/low or insufficient signal amplitude |
Code P0722 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0722 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.