P0405 fault code: what it means

P0405: EGR sensor A circuit low. On 2024 Elantra, Venue and Kona a recall (24V308) covers an electrical short inside the EGR valve that can cut drive power.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

short circuit inside the EGR valve assembly (recall 24V308)
EGR wiring or connector fault
sensor reference voltage short (often with P0642 / P0652)

P0405 by make

Hyundai

EGR sensor A circuit low. On 2024 Elantra, Venue and Kona a recall (24V308) covers an electrical short inside the EGR valve that can cut drive power.

Usual causes: short circuit inside the EGR valve assembly (recall 24V308); EGR wiring or connector fault; sensor reference voltage short (often with P0642 / P0652)

Isuzu

EGR position sensor circuit low.

Usual causes: faulty EGR valve/position sensor; wiring short

Toyota

EGR position sensor circuit low on D-4D diesels.

Usual causes: carbon jamming the EGR valve, confusing its position sensor; EGR valve wiring fault; failed EGR valve

What the repair usually costs

EGR valve replacement or cleanNZ$350–NZ$1,710 · A$330–A$1,630

Not sure what P0405 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.