What does code P248B mean?

Q: What does code P248B mean?

Reductant Heater A Sense Circuit High. P248B indicates that the powertrain control module has detected an abnormally high voltage on the sense circuit for the reductant heater, which is part of the diesel exhaust fluid system used to reduce emissions. The heater is designed to thaw frozen DEF in cold weather, and the sense circuit reports back to the computer whether the heater is functioning correctly; a high voltage reading typically means the circuit is open or shorted to voltage.

DTC codes / P24xx · Auxiliary emission controls / P248B

P248BReductant Heater A Sense Circuit High

P248B indicates that the powertrain control module has detected an abnormally high voltage on the sense circuit for the reductant heater, which is part of the diesel exhaust fluid system used to reduce emissions. The heater is designed to thaw frozen DEF in cold weather, and the sense circuit reports back to the computer whether the heater is functioning correctly; a high voltage reading typically means the circuit is open or shorted to voltage.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.