P056D fault code: what it means

P056D: AdBlue (reductant) control module voltage fault (diesel). AdBlue dosing may stop and warnings follow.

Engine and gearbox (powertrain) · Minor

Usual causes, most likely first

1. low battery voltage
2. wiring or fuse fault
3. reductant control module fault

P056D by make

Not sure what P056D 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.