P1056 fault code: what it means

P1056: Valvetronic motor supply voltage too low. Rough running or limp mode.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

Valvetronic relay or fuse fault
low battery voltage
wiring fault

P1056 by make

BMW

Valvetronic motor supply voltage too low. Rough running or limp mode.

Usual causes: Valvetronic relay or fuse fault; low battery voltage; wiring fault

Mazda

SKYACTIV-D cylinder 3 injection quantity too high. Rough idle, knock or smoke; often a leaking injector.

Usual causes: fuel injector No.3 leaking or sticking; injector code wrong; input sensor fault

Mini

Valvetronic motor supply voltage too low. Rough running or limp mode.

Usual causes: Valvetronic relay or fuse fault; low battery voltage; wiring fault

What the repair usually costs

Automatic transmission rebuild, 6-speed and up (sent to specialist)NZ$7,190–NZ$13,080 · A$6,190–A$11,830
DSG / dual-clutch mechatronic unit replacement (new or reman)NZ$4,300–NZ$7,160 · A$3,750–A$6,390
DSG mechatronic repair / rebuild (unit sent to specialist)NZ$2,070–NZ$4,800 · A$1,890–A$4,250
Electronic throttle body replaceNZ$470–NZ$1,290 · A$440–A$1,190

Not sure what P1056 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.