OBD-II code · Powertrain (generic)

P04D2 EGR Temperature Sensor C Circuit Intermittent or Erratic

Same as P04CE with intermittent or erratic signal. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.

Is it safe to drive with P04D2?

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

Common causes

  • Most likelyIntermittent contact at connector
  • Less likelyConnector with intermittent contact under vibration
  • Less likelyHarness routed against vibrating component

Symptoms

  • Check engine light on
  • Pinging or knocking under load
  • Power loss and hesitation
  • Possible rough idle
  • Failed emissions inspection (NOx)

Repair at a glance

Difficulty
Medium
DIY friendly
Often, with basic tools
Typical labour
0.6–1.6 h
Emissions test
Likely to fail
Parts involved
Egr Temperature Sensor C, Egr Temperature Wiring C

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