Functional Description - Integrated Electric Oil Pump (IEP)

DESCRIPTION: 

The IEP is located in the transmission sump to the rear of the valve body. The IEP is driven with a 12 volt brushless motor that has dedicated power and ground circuits that passes through the transmission case. The TCM sends requests for the desired IEP operating state using a Local Interface Network (LIN). The IEP reports feedback to the TCM such as rotor position, IEP internal temperature, rotor speed, current draw, IEP temperature, and power supply voltage. If an error is detected, the TCM will store the appropriate DTCs.

OPERATION: 

The IEP augments the chain driven mechanical oil pump when:

• The vehicle is stationary and the engine is running to provide lubrication and transmission cooling, when in EV mode, it may function to provide cooling only.
• Lubrication and cooling when in reverse and vehicle is in HEV or EV mode.
• The vehicle is moving forward for lubrication and cooling until the mechanical pump enough flow for different operating modes. As the mechanical pump capacity increases, the IEP speed will decrease and eventually shut off.
• The vehicle is moving forward and additional transmission fluid cooling is required, the pump may turn on.

• Provide target operational state (pump speed).
• Provide post run cooling.
• Provide auxiliary pump prime.
• Request idle speed.