Powertrain, generic · Auxiliary emission controls

P04E6 EGR Temperature Sensor D Circuit Range/Performance

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. Sensor D is the fourth of up to four EGR temperature sensors, conceivable on engines with high- and low-pressure EGR and a sensor before and after each cooler; it is usually an NTC whose low voltage means hot. No manufacturer document available to us uses sensor D; the description follows CARB and Ford's checks on sensor B as a comparison. P04E6 means the signal is electrically valid but implausible – for example it differs from other temperatures after a long stop, does not react when EGR opens, or freezes. Ford compares sensor B with intake and charge air after at least 6 hours off and flags more than 25 °C.

Likely causes

Sensor drifting (soot or oil crust, ageing)
Contact resistance in connector or harness (heat, corrosion)
Real temperature deviation: EGR cooler or bypass faulty, valve sticking
Comparison sensor faulty

Symptoms

  • Check engine light on
  • Usually no change in driving
  • EGR possibly reduced, higher NOx

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–300
Time0.5–2 h

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

Parts involved

egr temperature sensor dsensor wiringengine control module

Related codes

P04E5P04E7P04E8P04E9P04CFP041B

References: law.cornell.edu, fordservicecontent.com.