Electric Thermostat
| ITEM | DESCRIPTION |
|---|---|
| 1 | Hose connection - Engine outlet |
| 2 | Hose connection - Turbocharger, heater core and automatic transmission fluid return |
| 3 | Hose connection - Coolant expansion tank |
| 4 | Hose connection - Radiator lower hose |
| 5 | Electrical connector - Heater element |
| 6 | Hose connection - Variable coolant pump |
The electric thermostat contains a wax expansion element that incorporates a heater element. When energized, the heater element heats the wax expansion element, partially controlling the thermostat function along with engine coolant temperature control. Operation is therefore activated not only by the Engine Coolant Temperature (ECT), but as specified by the Powertrain Control Module (PCM). This enables a finer control of the opening and closing of the electric thermostat.
The increased wax expansion element temperature provides higher ECT during part load conditions and at low speed cycles. The increased ECT results in reduced friction in the engine, improved combustion in the cylinders and reduced fuel consumption and emissions. The heater element regulates the ECT during high load conditions and speed points. This protects the engine from thermal overload.