P076F Moderate Generic / SAE

P076F: Gear 7 Incorrect Ratio

What to do

Say whether the fault appears only at steady motorway speed. Seventh is an overdrive used when the engine is barely working, so a fault confined to it usually means something is just beginning to slip — and that is the cheapest moment in the whole progression to act.

Say when the transmission fluid was last changed, and whether it has ever been changed. Fluid condition is the single biggest factor in how long a gearbox lasts, and it is the cheapest thing on the list.

Ask for the speed sensors to be checked before any internal work. The ratio is calculated from two sensors, so a faulty one produces this with a perfectly healthy gearbox.

Do not ignore it because the car drives normally. Slip generates heat, heat destroys fluid, and degraded fluid causes more slip — the fault accelerates itself.

What this code means

The ratio measured in seventh gear is not the ratio seventh gear should give.

A ratio code is arithmetic rather than observation, and that is what makes it trustworthy. The module knows the input speed from the turbine sensor and the output speed from the output shaft sensor. Dividing one by the other gives the ratio actually being achieved, and each gear has exactly one correct answer. A mismatch means the gear commanded is not the gear delivered.

Seventh is an overdrive on almost every transmission that has one, and its position in the box shapes this fault. Overdrive gears are lightly loaded in normal driving — the engine is barely working at a motorway cruise — so an element that is beginning to slip can hold perfectly everywhere else and let go only here.

That makes a top-gear ratio code an early warning rather than a late one. It is often the first evidence of wear that will reach the lower gears in time.

The causes are the ratio family's, and they divide into whether the gear is being applied or held:

A slipping friction element, which is the commonest and the one this early warning is really about.
Insufficient hydraulic pressure to hold it, from fluid condition, a tired pump or a pressure control fault.
A speed sensor reading wrongly, in which case the ratio is fine and the arithmetic is not.

Check the sensors before condemning the gearbox — it is the cheap half of the diagnosis and it is quick.

Likely causes

Start here

Worn transmission friction element · specialist
Low or degraded transmission fluid · moderate

Less common

Symptoms

Components involved

Information, not instruction

CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.

Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.

Community experience

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