Powertrain, generic · Auxiliary emission controls

P041A EGR Temperature Sensor B Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

EGR temperature sensor B measures the gas temperature in the EGR path – for cooler monitoring, component protection and the EGR model. Whether it sits before or after the cooler depends on the maker: GM diesels have sensor A after and B before the cooler, Ford diesels sensor B after it. Like a coolant sensor it is an NTC, so a low voltage means hot. P041A is its general circuit code. No manufacturer document available to us uses it – GM and Ford report sensor B as P041B to P041D – so the description follows CARB's requirement to check input circuits for continuity and range. A substitute value is used and the EGR cooler check is suspended.

Likely causes

Connector or wire at the sensor
Sensor faulty
Engine module input

Symptoms

  • Check engine light on
  • Usually no change in driving
  • Substitute value used, EGR cooler check suspended

Repair estimate

DifficultyEasyDIY possible
Parts and labour€50–250
Time0.5–1.5 h

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

Parts involved

egr temperature sensor begr coolersensor wiringengine control module

Related codes

P041BP041CP041DP040AP040F

References: law.cornell.edu, fordservicecontent.com, gsi.ext.gm.com.