P046EEGR 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
- Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. Which part EGR sensors A and B are depends on the maker: sensor A is usually the position sensor of EGR valve A; GM's Duramax diesels of 2017/18 use sensor B for the coolant temperature sensor at the inlet of the high-pressure EGR cooler, FCA for the position sensor of the low-pressure valve. P046E means the signal of sensor B is valid but implausible. On GM's Duramax diesels, where it is the cooler inlet coolant temperature, the module compares it at a cold start after at least 8 hours off with two charge air temperature sensors; a deviation above 10 °C sets the code once per trip, MIL after two trips. A substitute value is then used and the EGR cooler check (P2457) is suspended.
- What you may notice
- Check engine light on
- Usually no change in driving
- EGR cooler check suspended
- Likely causes
- LikelyTemperature sensor drifting
- PossibleContact resistance at the connector
- RareReference sensor (charge air temperature) inaccurate without its own code
- RareLow coolant or air at the sensor
- 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: €40 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.