P0735: Gear 5 Incorrect Ratio
In gear 5, the transmission speeds do not match the expected ratio.
High risk
Drive gently and have it checked soon; slipping can damage the transmission.
Short answer · Can I keep driving with P0735?
Only gently. The transmission may slip or stay in one gear. Check the fluid level if your car allows it and have it checked soon.
What does P0735 mean?
Code P0735 means the transmission control unit compared the input and output speeds while gear 5 was selected and found a ratio that does not fit. A slipping clutch or band for that gear, low or worn fluid, a shift solenoid fault or a wrong speed signal can cause it.
What the car does when the code is set
The check engine or transmission warning comes on. You may notice slipping, flare when shifting, late engagement or the transmission staying in one gear.
How the system works
In each gear, an automatic transmission has a known ratio between its input and output speed. The transmission control unit compares the measured speeds with the expected ratio for the gear it has selected. If they do not match, a clutch or band is slipping, a shift has not been completed, or a speed signal is wrong. To protect the transmission, the control unit may lock it in one gear (limp mode) until the fault is cleared.
Common symptoms
Possible causes
Listed without ranking. The cause on your car depends on make, engine and mileage — see the maker notes below.
- Low or degraded transmission fluidClutches slip if the pressure is low.
- Worn clutches or bandsInternal wear lets the transmission slip.
- Faulty shift solenoids or valve bodyPressure is not controlled correctly.
- Speed sensor problemWrong speed readings give a wrong ratio calculation.
How it is diagnosed
- Check the fluidCheck level, colour and smell. Burnt fluid points to internal wear.
- Read gear ratio dataLive data shows which gear the ratio does not match.
- Check solenoids and sensorsTest them electrically and check other transmission codes.
- Pressure testA workshop measures line pressure to find internal problems.
Questions about P0735
Can a fluid change fix P0735?
Sometimes, if the fluid was low or worn and the clutches are not yet damaged. If the code returns, the transmission needs a closer inspection.
Will a fluid change fix it?
Only if old or low fluid is the cause. If clutches are worn, new fluid may help for a short time only.