My Jeep Liberty CRD has a Viscous pump with an electric clutch. When the parameters are met, it creates warm water and pumps directly to the heater core. Works great over 1000 RPM. Once it gets to temp, then it pumps engine coolant to the heater core.
From Green Diesel about the EcoD
For those that are not aware, the Ram ecodiesel is equipped with 3 PTC heaters in the HVAC system designed to provide quick cabin heat after starting the engine. A PTC is essentially a coil heating element in the air system ducts, similar to a hair dryer. All three PTC can pump out about 1000W.
The stock tune will idle at 1400 rpm is the HVAC requests the PCM to turn on the electrical heating elements (PTCs). For this to happen, it generally needs to be 50 F or colder outside and the coolant not warmed up. If you have the single-zone HVAC system, the temperature selector needs to be at maximum heat setting and the blower fan on at any level above zero. If you have the dual-zone HVAC it should only need the heat setting above the middle point and the blower on.
Granted, the 1000W PTC output is a bit low for the size of the cabin, this will help provide quicker heat than waiting for the coolant temps to rise.
TV - 2015 Ram Truck EcoDiesel
TV - 2006 Jeep Liberty Turbo Diesel (Retired to Daily Driver)
TT - 2015 Rockwood Roo 183
Nights Camping --- 2015 - 19 Camped | Winterized -- 2014 -18
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