Variable Coolant Pump
| Item | Description |
|---|---|
| 1 | Variable coolant pump shroud position sensor |
| 2 | Variable coolant pump shroud solenoid |
The variable coolant pump is installed at the front left of the cylinder block. A pulley attaches to the pump flange. The accessory drive belt drives the pulley at engine speed.
The Powertrain Control Module (PCM) determines the required level of cooling upon the following inputs:
- Cylinder head temperature
- Cylinder block temperature
- Ambient temperatures
- Engine coolant temperature
- Minimum flow map.
The calibration is able to control the variable coolant pump flow in 5 steps and is controlled by an open-loop map.
The control of the shroud solenoid is by a Pulse Width Modulation (PWM) signal from the PCM. The internal pressure within the pump acts against a return spring in the housing. Without a signal from the PCM the solenoid is de-energized. Therefore the shroud returns to its base position under spring force, resulting in full flow from the coolant pump.
For additional information, refer to: ENGINE COOLING