What it means
Output Shaft Speed Sensor Circuit Intermittent: the signal is intermittent or erratic. Often a loose connector or chafed wiring; a wiggle test often locates it.
At a glance
- Usually lights the check-engine light
How it works
The output speed sensor reports transmission output-shaft speed to the control module for shift control. P0723 sets when that signal cuts in and out or becomes erratic, often because vibration or movement interrupts a connector or damaged section of wiring.
Common causes
Most likely first.
- Intermittent contact at connector
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Review freeze-frame data and scan for related speed-sensor codes, then check live output speed for dropouts during the conditions recorded.
- If safe, monitor output speed during a short drive and note whether the reading drops or jumps over bumps, during shifts, or with vehicle vibration.
- Inspect the output speed sensor connector for loose fit, corrosion, or moisture and follow the harness for chafing or contact with vibrating parts.
- Gently move the accessible sensor harness while monitoring live data or circuit continuity to locate an intermittent connection.
- Test the output speed sensor and its wiring under the conditions needed to reproduce the dropout, comparing results with the wiring diagram and manufacturer's specification.
Common fixes
- Secure a loose output speed sensor connector and clean corroded terminals.
- Repair chafed wiring and reroute it away from vibrating or moving parts.
- Replace damaged connector terminals or seals that allow intermittent contact.
- Replace the output speed sensor if its signal drops out with the wiring and connection verified.
Can I keep driving?
Shifting may become unpredictable when the speed signal drops out, so avoid long trips or heavy loads until repaired. Stop if the transmission slips or loses safe, predictable shifting.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.