P0735 – Gear 5 Incorrect Ratio (OBD2)
P0735 means "Gear 5 Incorrect Ratio". These codes mean the gearbox did not achieve the expected gear ratio or shift: a gear is slipping, the shift took too long or too short, or more than one gear was engaged.
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P0735 quick summary
| Fault code | P0735 |
|---|---|
| Meaning | Gear 5 Incorrect Ratio |
| System | Powertrain (Engine & Transmission) |
| Vehicles | Generic OBD2 |
| Severity | High |
| Can I drive? | Not recommended. A slipping gearbox wears rapidly; drive only gently and as short as possible to a workshop. |
| Repair cost | €100 – €4,000 |
What incorrect gear ratio and shift codes mean
The control unit calculates the actual gear ratio by comparing input and output shaft speeds. If the ratio does not match the commanded gear, it stores an incorrect ratio code for that gear (P0729–P0736). Shift malfunction codes (P0780–P0784, P0829) mean a specific shift was not completed correctly; P0893–P0896 cover multiple gears engaged, component slipping and shift times.
These are mechanical or hydraulic problems more often than electrical ones: low or degraded fluid, worn clutches or bands, sticking valves in the valve body or a weak pump. A faulty speed sensor can also make the calculated ratio wrong.
Driving with a slipping gearbox generates heat and debris and quickly makes the damage worse.
On VAG vehicles (VW, Audi, Škoda, Seat, Cupra), VCDS and older VAG testers can show this code as the five-digit VAG code 17119 (P0735). Both numbers mean the same fault.
Symptoms of P0735
- Engine revs flare between gears
- Slipping, especially under load
- Harsh or delayed shifts
- Gearbox stuck in one gear
- Burnt-smelling fluid
Most common causes of P0735 (most likely first)
Mechanic's Pro Tip
A fluid service can help with shift quality problems caused by old fluid, but it will not fix worn clutches. If the fluid is black and smells burnt and there is friction material on the magnet, the gearbox needs an overhaul.
1.Low or degraded gearbox fluid
Most likely2.Worn clutches, bands or brakes in the gearbox
3.Sticking valve or solenoid in the valve body
4.Weak oil pump or internal leak
5.Faulty speed sensor giving a false ratio
Step-by-step diagnostic guide
- 1
Read codes and ratio data
Read the transmission codes and watch commanded gear, actual ratio and slip in live data.
- 2
Check fluid level and condition
Check fluid level, colour and smell; look for debris on the magnet or in the filter.
- 3
Check speed sensors
Make sure input and output speed signals are correct.
- 4
Check line pressure
Measure line pressure with a gauge where possible.
Multimeter: Compare with the manufacturer's specification for each gear and condition.
- 5
Repair
Depending on the cause: fluid service, valve body repair, solenoid replacement or gearbox overhaul; then run adaptations.
Frequently asked questions
Can I keep driving with P0735?
Not recommended. A slipping gearbox wears rapidly; drive only gently and as short as possible to a workshop.
How much does it cost to fix P0735?
Typical repair costs are 100 € – 4000 €, depending on the cause and the vehicle. The most common fixes are: low or degraded gearbox fluid; worn clutches, bands or brakes in the gearbox; sticking valve or solenoid in the valve body. Always confirm the cause with the tests above before buying parts.
Can new fluid fix an incorrect ratio code?
Sometimes, if the cause is low or degraded fluid. If clutches are worn, new fluid will not help.
What is a 'flare' between gears?
A short rise in engine speed during a shift because the next gear does not engage quickly enough – a sign of slipping.
What is the difference between P0735 and similar codes?
P0735 belongs to a group of codes for the same component that differ in the type or location of the fault: P0732 – Gear 2 Incorrect Ratio; P0733 – Gear 3 Incorrect Ratio; P0734 – Gear 4 Incorrect Ratio; P0736 – Reverse Incorrect Ratio; P0780 – Shift Malfunction; P0781 – 1-2 Shift Malfunction. The tests on this page apply to the whole group; the type of fault tells you where to start.
Related fault codes
This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.