P041BEGR Temperature Sensor B Circuit Range/Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- 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. P041B is its plausibility check. Ford diesels compare it at a cold start, after at least 6 hours off, with two other air temperatures (limit 25 °C, 30 °C with a block heater); GM diesels set the code if it barely changes after 8 hours off and EGR operation. Ford petrol engines list P041B with the electrical checks (5 s). MIL after two trips.
- What you may notice
- Check engine light on
- Usually no change in driving
- Substitute value used, EGR cooler check suspended
- Likely causes
- LikelySensor drifting or sluggish (soot)
- PossibleContact resistance in the connector
- PossibleNo EGR flow (GM stuck test)
- RareComparison sensor (intake or charge air temperature) faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €50 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.