OBD-II code · Powertrain (generic)
P0730 Incorrect Gear Ratio
The ratio between input and output speed does not match any expected gear. Indicates slippage, valve body fault or sensor inaccuracy without identifying a specific gear.
Is it safe to drive with P0730?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyInternal slippage
- PossibleValve body fault
- Less likelySpeed sensor reading inaccurate
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
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 2–12 h
- Emissions test
- Usually unaffected
- Parts involved
- Automatic Transmission, Valve Body, Speed Sensor
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.