Coolant Valves

The coolant valves control the coolant flow to each side of the heater core. The coolant valves are installed in the engine compartment on a bracket attached to the side of the left-hand (LH) suspension turret.

Each coolant valve is a normally open solenoid valve controlled by a pulse width modulation (PWM) signal from the automatic temperature control (ATC) module. The automatic temperature control (ATC) module changes the length of time the coolant valve is open each duty cycle between 0 second (valve closed) and 3.6 seconds (valve held open). On the automatic system, the pulse width modulation (PWM) signals to the two valves are phase offset by 1.8 seconds to reduce coolant flow fluctuations.