Cabin Heater Coolant Pump

The cabin heater coolant pump is available on vehicles equipped with Auto Start-Stop feature only. 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. Refer to the Owner's Literature, Unique Driving Characteristics, for full Auto Start-Stop enabling/disabling information.

The PCM sends a PWM signal to the cabin heater coolant pump based upon the:

• Auto Start-Stop mode enabled
• HVAC system temperature control setting (requesting heat)
• Ambient air temperature
• Engine coolant temperature
• Engine RPM
• Vehicle speed