OBD-II · Engine and powertrain (P)
P0730
Incorrect gear ratio
What it means
The ratio between gearbox input and output speed does not match the selected gear, which usually means slipping.
Symptoms
- engine revs flare during or after a gear change
- slipping or delayed engagement
- limp mode
- gearbox warning light
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | low or degraded transmission fluid |
| 02 | worn clutches in the gearbox |
| 03 | shift solenoid or valve body fault |
| 04 | faulty speed sensor |
| 05 | mechatronic unit fault |
What to check, step by step
- 01Check the transmission fluid level and condition with the correct procedure and temperature
- 02Read transmission codes and the ratio/slip values in live data
- 03Check the input and output speed sensors
- 04Refer to a transmission specialist for pressure tests and internal inspection