Cabin Heater Coolant Pump

Vehicles equipped with the 3.5L EcoBoost engine have the auto start-stop feature as standard equipment, which includes a cabin heater coolant pump. The cabin heater coolant pump provides coolant to the heater core whenever the HVAC system requests heat and the vehicle is in auto start-stop mode. The PCM sends a PWM signal to control the cabin heater coolant pump. Refer to the Owner's Literature, Unique Driving Characteristics for full auto start-stop enabling/disabling information.