P0486 EGR Sensor B Circuit

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.

Likely causes

Symptoms

• Check engine light on
• EGR switched off, usually no noticeable change
• Higher NOx

Repair estimate

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

Parts involved

Related codes

References: law.cornell.edu, static.nhtsa.gov, gsi.ext.gm.com.