P0730 fault code: what it means

P0730: Incorrect gear ratio; the gearbox is slipping or not in the gear it should be.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

low or burnt transmission fluid
worn clutches or bands inside the gearbox
faulty shift solenoid or valve body

P0730 by make

Ford

Incorrect gear ratio (general): the gearbox's input and output speeds do not match the selected gear, meaning slip.

Usual causes: internal clutch slip; valve body pressure loss; low or worn fluid

Honda

Incorrect gear ratio: the conventional Honda automatic is slipping. External clutch pressure switches are a common Honda trigger before internal wear.

Usual causes: low or dirty ATF (use genuine Honda ATF); faulty transmission fluid pressure switch; shift solenoid fault; worn clutch packs / blocked internal screens

Hyundai

Incorrect gear ratio: the transmission is slipping. On the DCT usually clutch slip; on the 6-speed auto valve body or clutch wear.

Usual causes: worn DCT dry clutch pack; low or worn transmission fluid; worn A6 valve body bores or clutch packs; IVT belt/pulley slip

Jeep

Incorrect gear ratio. Gearbox is slipping or the ratio doesn't match the gear asked for.

Usual causes: low or old transmission fluid; worn clutches in the gearbox; valve body or solenoid fault

Kia

Incorrect gear ratio: the transmission is slipping.

Usual causes: worn DCT clutch pack; IVT belt/pulley slip; worn A6 valve body or clutch packs; low or worn fluid

Mercedes-Benz

Incorrect gear ratio (gearbox slipping or wrong gear). On 7G-Tronic can be valve body, solenoid O-ring or clutch wear.

Usual causes: low transmission fluid; valve body/solenoid fault (leaking solenoid O-rings); worn or burnt clutches

Mitsubishi

Incorrect ratio: CVT belt/pulley ratio does not match what was commanded, often slip.

Usual causes: CVT belt and pulley slip (internal wear); low or degraded CVT fluid; valve body or pressure control fault

What the repair usually costs

DSG dry dual-clutch pack replacement (DQ200 7-speed)NZ$1,620–NZ$2,970 · A$1,600–A$2,880
DSG wet dual-clutch pack replacement (DQ250 / DQ381 6/7-speed)NZ$2,700–NZ$4,840 · A$2,570–A$4,550
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

Not sure what P0730 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.