P0203 fault code: what it means

P0203: Cylinder 3 fuel injector circuit fault.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

corroded or poorly latched injector connector
damaged injector wiring
failed injector coil

P0203 by make

Isuzu

Injector cylinder 3 circuit fault.

Usual causes: injector wiring or connector; failed injector

Mazda

Fuel injector No.3 circuit fault (open or abnormal). Seen on both SkyActiv-G and SkyActiv-D.

Usual causes: injector No.3 connector or wiring; fuel injector No.3; PCM connector

What the repair usually costs

Petrol fuel injectors (port injection, set)NZ$430–NZ$1,420 · A$400–A$1,360

Not sure what P0203 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.