What P0723 means
The output shaft speed sensor (Hall or inductive) reports the speed of the transmission output; it gives the gear ratio together with input speed and on many vehicles also the road speed for speedometer and cruise control.
How the engine computer detects it
P0723 means the output speed drops or jumps briefly. GM's 2006 tables flag road speed falling below 61 rpm while driving; the 2019–2025 modules count sudden drops (for example 700 rpm) and fail after more than five, after one trip. In Ford vehicles the ZF 6HP26 flags a drop of more than 1000 rpm with the converter clutch locked, the CFT30 more than 6000 rpm per second. The speedometer needle twitches, shifts become erratic and limp mode may follow at times. Loose contacts are the usual cause.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Speedometer needle twitches or drops briefly
- Occasional wrong shifts or downshift jolts
- Warning lamp
- Limp mode at times
Common causes
- Loose contact, corroded connector or chafing Most likely
- Electrical interference (shielding, ground, added consumers) Possible
- Metal debris on the sensor or loose mounting Possible
- Sensor faulty internally (temperature-dependent) Possible
How to diagnose P0723
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: output speed sensor, sensor wiring, transmission control module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 7
- Transmission
- 23
- Specific fault
Questions drivers ask
Can I drive with code P0723?
Drive gently and only as far as you need to. The engine computer may limit power to protect the engine, so avoid highways and heavy traffic until it's fixed. If the check engine light starts flashing, pull over.
Will my car pass an emissions inspection with P0723?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Can I fix P0723 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: medium. Start with the cheapest checks before replacing expensive parts.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.