P041EEGR Temperature Sensor B Circuit Intermittent/Erratic
- 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
- Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. EGR temperature sensor B is the second temperature sensor in the EGR path; on GM diesels it sits before the cooler, on Ford diesels after it. P041E means its signal jumps. GM's diesels of 2016–18, the only documented users, set it when the measured resistance changes by more than 25 Ω between two samples 100 ms apart – faster than any real temperature change, so a loose contact or cracked sensor is the cause (40 of 50 samples, MIL after two trips). Dependent checks such as EGR cooler efficiency are then suspended.
- What you may notice
- Check engine light on, may come and go
- Usually no noticeable symptom
- Further EGR temperature or cooler checks suspended
- Likely causes
- LikelyLoose contact or corrosion at the sensor connector
- PossibleHarness chafed or broken (heat at the EGR pipe)
- PossibleSensor cracked internally (thermal cycling)
- RareEngine module or ground connection
- 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: €30 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.