P0730: Incorrect Gear Ratio
The transmission's input and output speeds don't match any gear, which means it's slipping or not engaging properly.
Green, yellow, red: three ways P0730 can look
The same code can be a quick fix or a reason to pull over. Match your situation to the closest example.
Keep an eye on it
Set once with full, clean fluid.
Schedule a repair
Slipping. Have it checked right away; it gets worse fast.
Stop and get help
Slipping badly or no movement. Stop driving and tow it.
Symptoms you might notice
- Slipping
- Engine revs up without speeding up
- Harsh or delayed shifts
Common causes, cheapest first
- Low or burnt fluid
- Worn clutches inside the transmission
- Failing shift solenoid or valve body
- Speed sensor fault
What you can check before calling
- Check fluid level and smell (burnt is bad)
A code points to a system, not a part. Replacing parts based on the code alone is how people spend money without fixing the problem. Testing confirms the cause first.
Want the full story? Read our guide: Do you really need a transmission fluid change?.
Generic codes (second character 0) mean the same thing on every vehicle. Some manufacturers add their own details, so check service information for your exact vehicle.
Related codes
More transmission codes
Look up another code
Cummins fault code (like 1922), J1939 SPN and FMI (like SPN 3251 FMI 0), or an OBD-II code (like P0420).
Questions
What does P0730 mean?
P0730 means "Incorrect Gear Ratio". The transmission's input and output speeds don't match any gear, which means it's slipping or not engaging properly.
Can I drive with code P0730?
It depends on what the vehicle is doing. Green: Set once with full, clean fluid. Yellow: Slipping. Have it checked right away; it gets worse fast. Red: Slipping badly or no movement. Stop driving and tow it.
What causes P0730?
The most common causes are: low or burnt fluid; worn clutches inside the transmission; failing shift solenoid or valve body.
Is P0730 a serious code?
It can be. Slipping badly or no movement. Stop driving and tow it.
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