P0722
Output Speed Sensor Range/Performance
Powertrain Transmission Control Speed sensor malfunction 🟡 Moderate — Fix within a week
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What This Actually Means
In plain language — no jargon

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.

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Symptoms You May Notice
3 known symptoms for this code
Transmission shifting harshly or refusing to shift gears
Check Engine Light illuminated on dashboard
Reduced fuel economy and sluggish acceleration
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Embedded Systems Insight
What the ECU/ECM is actually computing

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.

Voltage & Parameter Thresholds

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
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Transmission fluid and filter
Replace fluid and filter as contamination can interfere with sensor operation; inspect for metal debris indicating internal transmission wear.
2
Output speed sensor connector and wiring
Inspect connector for corrosion, loose pins, and wiring for damage; clean or reseat connections at the transmission.
3
Output speed sensor
Replace the sensor if wiring and connections are clean; sensor typically located on transmission case near output shaft.