Electric Thermostat
| ITEM | DESCRIPTION |
|---|---|
| 1 | Thermostatic control valve |
| 2 | Electric thermostat connector |
| 3 | Electric thermostat |
The electric thermostat is located on the front of the cylinder block, on the left side.
The thermostat housing contains a wax expansion element. Inside the wax element is a heater element. When energized the heating element heats the wax element, partially controlling the thermostat function along with engine coolant temperature control. Operation is therefore performed not only by the engine coolant temperature, but as specified by the Powertrain Control Module (PCM). This method provides a finer control of the opening and closing of the electric thermostat.
Operation of the electric thermostat is controlled by the PCM upon the following inputs:
- Engine load
- Vehicle speed
- Engine Coolant Temperature (ECT) sensor 1
- Engine Coolant Temperature (ECT) sensor 2
- Intake air temperature.
The electric thermostat has the following connections:
- A switched power supply from the PCM relay, located in the Engine Junction Box (EJB).
- A hardwired connection to the PCM.
When the PCM starts to regulate the system, the PCM supplies a ground path for the heater element in the electric thermostat. This causes the element to expand and increase the opening dimension of the electric thermostat.
The thermostatic control valve incorporates a wax thermostat which regulate the engine coolant flow in the split cooling system. The thermostatic control valve independently controls the engine coolant flow in the cylinder block, improving engine warm-up times. The electric thermostat and the thermostatic control valve work together to regulate the engine coolant temperature.
For additional information, refer to: ENGINE COOLING