P0486EGR Sensor B Circuit
- 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 sensor B is depends on the maker: FCA uses it for the position sensor of the low-pressure EGR valve, GM's Duramax diesels for the coolant temperature sensor at the EGR cooler inlet. P0486 is its general circuit fault without a low or high assignment. No manufacturer document available to us uses it – makers report sensor B as P0407/P0408, P046E and P046F – so the description follows CARB's input component rules. EGR is then switched off or uses a substitute value.
- What you may notice
- Check engine light on
- EGR switched off, usually no noticeable change
- Higher NOx
- Likely causes
- LikelyConnector or harness to sensor B corroded or open (heat at the exhaust)
- PossibleSensor B faulty
- Rare5 V reference or ground disturbed
- RareEngine module or software
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €50 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.