Cabin Heater Coolant Pump - vehicles equipped with Auto-Start-Stop
WARNING: This page is about a different variant/trim than selected.
The cabin heater coolant pump is available on vehicles equipped with Auto-Start-Stop feature. 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 cabin heater coolant pump provides coolant flow to the engine when the engine is shut down to provide additional cooling to the engine components. This pump varies in runtime. With the engine shutdown and the cabin heater coolant pump in normal operation there can be a noticeable humming sound. 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 Revolutions Per Minute (RPM)
- Vehicle speed