Kia Optima Hybrid: Hydraulic System / Electric Oil Pump (EOP) Description and Operation

Kia Optima Hybrid (TF HEV) 2016-2020 Service Manual / Automatic Transaxle System / Hydraulic System / Electric Oil Pump (EOP) Description and Operation

Description

This transaxle has a standard Mechanical Oil Pump (MOP) linked to the input shaft to generates oil pressure when input shaft rotates. Being a hybrid, this transaxle also has an Electric Oil Pump (EOP). Because the hybrid features Auto-Stop which starts and stops the engine as needed. The Auto-Stop feature prevents the Mechanical Oil Pump (MOP) from operating and building enough pressure for the transaxle to operate. When the vehicle comes to a stop with the engine off, Mechanical Oil Pump (MOP) cannot generate sufficient oil pressure during the initial startup (below 5 KPH) or during low speed driving. For these reasons, the Electric Oil Pump (EOP) takes on this role as an additional device that can generate the required oil pressure when the vehicle comes to a stop or during low speed driving. The Electric Oil Pump (EOP) not only supplies oil pressure to the Under Drive Brake (UD/B), but it also feeds the oil pressure to the Engine Clutch (E/C).

–	While low speed driving or engine auto stop, it supplies oil pressure to Under Drive Brake (UD/B) of automatic transaxle.

–	To supply oil pressure to Engine Clutch (E/C) when engine power is needed.

Electric Oil Pump (EOP) Operation

Starting & Creep driving (Low speed)	Element	Operation	Description
	HSG	Stop	- Vehicle moves by motor (EV mode) > EOP operates in order to supply hydraulic pressure for 1st gear in A/T at the time of vehicle starting
	Motor	Rotation
	Engine	Stop
	E/Clutch	Disengage
	EOP	Rotation
	A/T	1st gear
Auto Stop	Element	Operation	Description
	HSG	Stop	- EOP operates to supply the hydraulic pressure (in order to be ready to vehicle starting) > You can hear the EOP operating sound
	Motor	Stop
	Engine	Stop
	E/Clutch	Disengage
	EOP	Rotation
	A/T	D range

ATF Warmer Repair procedures

Removal 1. Remove the under cover (A). Tightening torque : 7.8 ~ 11.8N.m (0.8 ~ 1.2kgf.m, 5.8 ~ 8.7 lb-ft) 2. Drain the coolant of engine & transaxle cooling system. (Refer to Engine Mechanical System ...

Electric Oil Pump (EOP) Specifications

Specifications PumpPumping capacityAbout 6.46cc per one revolutionTypeInternal gearMotorType Brushless DC motor (3 phases)Torque Rated 1.5 N.mSpeed range100~2,500 rpm ...

Other information:

Kia Optima Hybrid (TF HEV) 2016-2020 Service Manual: Repair procedures

Fuel Pressure Test 1. Release the residual pressure in fuel line (Refer to “Release Residual Pressure in Fuel Line” in this group). When removing the fuel pump relay, a Diagnostic Trouble Code (DTC) may occur. Delete the code with the GDS after completion of “Release Residual Pressure ...

Kia Optima Hybrid (TF HEV) 2016-2020 Service Manual: Brake Actuation Unit Repair procedures

Removal 1. Turn ignition switch OFF and disconnect the negative (-) battery cable. 2. Remove the air duct (A). 3. Remove air cleaner assembly (B). 4. Disconnect the brake fluid level switch connector (A), and remove the reservoir cap. Be sure to completely remove foreign substances from ...