Chevrolet Volt Coolant Valve

Chevrolet Volt Heater control valve is a 3 way valve that supplies heater system with fluid either from HV heater side or from ICE engine side.
Control is done by 5V signal.
This control valve is located in the middle left side of the hood.

Coolant Heater Control Valve position

Pin1 – 12V
Pin2 – Solenoid control signal
Pin3 – 5V reference
Pin4 – Solenoid Position signal
Pin5 - Low reference
Pin6 - GND

Duty cycle 75% = link position = flow from top to bottom outlet and 3,3V on sensor signal pin (#4) Duty cycle 25% = bypass position = flow from top to right outlet and 2V on sensor signal pin (#4)
More data here: https://www.diyelectriccar.com/threads/chevy-volt-opel-ampera-3-way-valve.199131/

Coolant control valve

Coolant Heater Control Valve