What does code P05F6 mean?

Q: What does code P05F6 mean?

Exhaust Aftertreatment Power Relay Control Circuit Stuck On. P05F6 means the engine control module (ECM) has commanded the exhaust aftertreatment power relay off, but the relay's control circuit is still being sensed as energized, so the circuit is stuck on. The ECM detects this by comparing its output command with the feedback voltage on the relay control circuit, and it sets the code when the feedback stays high longer than expected.

DTC codes / P05xx · Vehicle speed, idle control and auxiliary inputs / P05F6

P05F6Exhaust Aftertreatment Power Relay Control Circuit Stuck On

P05F6 means the engine control module (ECM) has commanded the exhaust aftertreatment power relay off, but the relay's control circuit is still being sensed as energized, so the circuit is stuck on. The ECM detects this by comparing its output command with the feedback voltage on the relay control circuit, and it sets the code when the feedback stays high longer than expected.

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.