What does code P05F8 mean?

Q: What does code P05F8 mean?

Reductant Heater Control Module Performance. P05F8 indicates that the reductant heater control module has failed a performance self-test or its commanded heating effect does not match the expected temperature rise within the time allowed by the strategy. The engine control module monitors heater current, voltage drop, and temperature response to verify that the reductant heater control module can properly energize and regulate the heater circuit.

DTC codes / P05xx · Vehicle speed, idle control and auxiliary inputs / P05F8

P05F8Reductant Heater Control Module Performance

P05F8 indicates that the reductant heater control module has failed a performance self-test or its commanded heating effect does not match the expected temperature rise within the time allowed by the strategy. The engine control module monitors heater current, voltage drop, and temperature response to verify that the reductant heater control module can properly energize and regulate the heater circuit.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaVehicle speed, idle control and auxiliary inputs

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