Powertrain, generic · Auxiliary emission controls

P04D2 EGR Temperature Sensor C Circuit Intermittent/Erratic

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. P04D2 means brief excursions out of range or implausibly fast temperature jumps. FCA lists sensor C codes for its part 68142905A (Ram 2014 6.4 and 3.0 litre, Jeep and Dodge 3.6 Pentastar 2016) together with P040B, P0401 and P2457. GM checks sensor B in the same way with a jump test (40 of 50 samples). A Mack/Volvo truck bulletin names worn connector contacts at the EGR temperature sensor as a typical cause of wrong readings.

Likely causes

Loose contact or fretting at the connector pins
Wire chafing intermittently (vibration, heat)
Sensor with an internal contact fault

Symptoms

  • Check engine light on, may come and go
  • Usually no change in driving

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

P04CEP04CFP04D0P04D1P040EP041E

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