Powertrain, generic · Auxiliary emission controls

P04D1 EGR Temperature Sensor C Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. The code standard allows up to four EGR temperature sensors, A to D – for example before and after the cooler, or in the high- and low-pressure circuits; which is which depends on the maker. Sensor C is the third of them, usually an NTC whose low voltage means hot. P04D1 means its signal voltage is above the upper limit – extremely cold, or more often an open sensor, signal or ground line, or a short to 5 V. Besides FCA, GM documents it on the 3.0-litre Duramax LM2 of 2020–21, where it is called EGR temperature sensor 2; if the diagnosis leads to the engine module, module and sensor are replaced together. For sensor B Ford diesels use above 4.95 V.

Likely causes

Signal or ground line open, connector off or corroded
Sensor open internally (element broken)
Signal shorted to 5 V or positive
Engine module input

Symptoms

  • Check engine light on
  • Usually no change in driving (EGR on a substitute value or off)
  • Possibly EGR flow or cooler codes (P0401, P2457)

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–300
Time0.5–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

egr temperature sensor csensor wiringengine control module

Related codes

P04CEP04D0P04CFP04D2P040DP041D

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.