Component Functional Description - Oil Pump Solenoid

The mechanical Engine Oil Pump operates in two pressure modes described below. The Powertrain Control Module (PCM) switches the pump between modes based on the oil temperature, coolant temperature, and engine operating conditions.

• Low Mode:  To operate the pump in low mode the PCM commands the High Side Driver (HSD) control on, energizing the Oil Pump Solenoid. The Engine Oil Pump is operated in low mode between idle and approximately 2600 RPM.
• High Mode:  To operate the pump in high mode the PCM commands the HSD control off, de-energizing the Oil Pump Solenoid. The PCM will typically switch the pump from low to high mode when the engine speed increases over approximately 2650 to 2800 RPM.
• In some instances the system can change to high pressure mode before the engine speed listed when the PCM detects that the engine load increases above a calibrated threshold. This can sometimes be determined by monitoring the oil pressure reading. Typically pressure will increase in relation to engine speed. When the system changes modes the pressure may spike suddenly up or down depending on which mode is being commanded.

See the oil pressure specifications in the table below: