OBD-II code · Powertrain (generic)

P0405 Exhaust Gas Recirculation Sensor "A" Circuit Low

Exhaust Gas Recirculation Sensor "A" Circuit Low: the signal voltage is below the expected range. Without valid EGR feedback the ECU disables exhaust gas recirculation and may set further EGR codes.

Is it safe to drive with P0405?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyEGR position sensor failed
  • PossibleWiring or connector fault
  • Less likelyConnector pins corroded - high contact resistance

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.3–2 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Egr Position Sensor, Egr Sensor Wiring

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.