P0729
Gear 6 Incorrect Ratio
What it means
P0729 means Gear 6 Incorrect Ratio.
Check these first
- Low or degraded transmission fluid
- A slipping clutch pack for sixth gear
- A failing output or speed sensor
- A worn gear set or bearing
- A TCM calibration problem
What to do next
- Check the fluid level and condition first
- Compare input and output speed on a scan tool
- Read the commanded and actual ratio for sixth
- Inspect the speed sensors for debris
- Service the fluid and filter if it is dirty
- Clear the code and retest
Look up another code
Enter a full code or a symptom. Press / to search. How to read a code
Type a code above, or start from a symptom or a common code.
Updated
Generic SAE J2012 definition. Last updated 2026-10-10.