What does code P25AF mean?

DTC codes / P25xx · Vehicle speed, idle control and auxiliary inputs / P25AF

P25AFCoolant Temperature Control Module Requested MIL Illumination

P25AF is a generic powertrain code indicating that the engine control module (ECM) has received a request from the coolant temperature control module to illuminate the malfunction indicator lamp (MIL). A separate module responsible for managing coolant temperature has decided that a fault exists and has asked the ECM to turn on the check engine light, so the ECM stores this code as a record of that request.

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.