Valve, 3-Way Coolant: Operation: Operation

WARNING: This page is about a different car, the 2016 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.

The purpose of the three way coolant valve is to direct coolant not required for cabin heat to the transmission heater. Coolant is first directed from the engine to the three way valve, which directs the coolant to the transmission heater and the heater core. Coolant flow volume to the transmission heater and the heater core is controlled by a pulse width modulated ball valve located upstream of the cabin heater coolant supply. The coolant valve receives a signal from the Powertrain Control Module (PCM) directing it to turn the ball valve in accordance with cabin heater demand. When cabin compartment heat demand is high (Maximum heat/High blower motor speed), the majority of the coolant is diverted to the heater core. By getting coolant to the transmission heater, it allows the transmission to get to ideal operating temperature quicker so the transmission is operating efficiently.

The three way coolant valve is controlled and monitored by the PCM. The three way coolant valve has dedicated Diagnostic Trouble Codes (DTCs) that can be stored by the PCM.