P0731 fault code: what it means

P0731: Incorrect 1st gear ratio. On the 10R80 the CDF clutch drum sleeve moving and leaking is a known cause.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

CDF clutch drum sleeve leak
worn clutches
valve body pressure loss

P0731 by make

Ford

Incorrect 1st gear ratio. On the 10R80 the CDF clutch drum sleeve moving and leaking is a known cause.

Usual causes: CDF clutch drum sleeve leak; worn clutches; valve body pressure loss

Hyundai

First gear ratio incorrect. On the 7-speed DCT this points at the odd-gear clutch side.

Usual causes: slipping odd-gear clutch or gear actuator fault (DCT); low or worn transmission fluid; worn clutch packs or solenoid (conventional auto)

Kia

First gear ratio incorrect.

Usual causes: worn A6MF valve body bores / pressure solenoids; low or dirty transmission fluid; worn clutch packs; odd-gear clutch slip (DCT)

What the repair usually costs

Automatic transmission fluid service, drain and refill (car)NZ$210–NZ$470 · A$210–A$450
Automatic transmission fluid service (SUV / ute / 4WD)NZ$300–NZ$680 · A$290–A$650
Automatic transmission service with pan / filter (European ZF / Mercedes)NZ$610–NZ$1,240 · A$570–A$1,160
CVT fluid service (car)NZ$250–NZ$580 · A$250–A$550

Not sure what P0731 means on your car? Ask Credov.

Before you clear it

Write the code down or photograph the scanner first. A code that comes straight back after clearing points to a fault that is still there. A car whose codes were cleared just before you arrived may be hiding one: the scanner's readiness monitors show "not ready" for a while after codes are cleared.

Researched by Credov from manufacturer and workshop sources. A fault code points to where a fault may be; a workshop confirms it with a diagnosis. Browse all fault codes.