Motor Electronics Cooling System (MECS) Pump

The motor electronics cooling system is required to maintain an acceptable temperature for the transaxle and the DC/DC converter. The system temperature is monitored by the motor electronics coolant temperature (MECT) sensor, which is an input to the PCM. The PCM commands the MECS pump using the MECS pump relay. The MECS pump is commanded on whenever the traction battery contractors are closed. The coolant in the system flows in a loop from the MECS pump, to the transaxle, then into the MECS radiator bottom hose port, out of the top hose port of the MECS radiator, into the DC/DC converter, and back into the MECS pump. The cooling system has a degassing system that is connected in parallel between the MECS radiator and the MECS pump. The degassing system bleeds air/gases into the degas reservoir.

Fig 1: Identifying Motor Electronics Cooling System (MECS) Pump

Courtesy of FORD MOTOR CO.

Fig 2: Identifying Motor Electronics Coolant Flow

Courtesy of FORD MOTOR CO.