Outline
The oil pump has a mechanism for feedback control of oil pressure. As a result, an oil pressure increase of more than the set pressure is suppressed and oil pump drive resistance is reduced. In addition, because the set pressure can be changed (oil pressure two-step control) by operating the engine oil solenoid valve, the oil pump drive resistance is reduced even during low speed/low to medium loads.
Purpose, Function
The oil pump suctions the engine oil in the oil pan through the oil strainer and pumps engine oil into the engine.
Construction
The oil pump is installed on the lower part of the cylinder block (in oil pan).

With the adoption of the chain drive type oil pump, the diameter of the rotor is reduced. As a result, the oil pump drive resistance has been reduced.
The oil pump consists of the following parts:

The relief valve and bypass valve is pushed and opened if oil pressure increases excessively when starting an extremely cold engine. As a result, the engine oil flows and excessive oil pressure increase is suppressed.
When the relief valve is pushed and opened, engine oil flows. As a result, the oil pressure decreases and the oil pump drive resistance is reduced.

Operation
The oil pump adjusts oil pressure in two steps (low oil pressure setting, high oil pressure setting) by switching the oil passage with the operation of the engine oil solenoid valve. For the operation condition of the engine oil solenoid valve, refer to CONTROL SYSTEM..
When the engine oil solenoid valve is turned ON, oil pressure is also applied to the upper part of the pilot valve. Because the oil pressure applied to the upper and lower parts of the pilot valve is almost same, the pilot valve is pressed up by the spring force.
Oil pressure is applied to the upper part of the relief valve.
When oil pressure exceeds the relief valve opening pressure, the relief valve is pressed down and engine oil flows. (oil pressure decrease)
When oil pressure is less than the relief valve opening pressure, the relief valve closes. As a result, engine oil flowing stops (oil pressure increase).
Oil pressure is adjusted by repeating Step (c) to (d).

When oil pressure exceeds the pilot valve opening pressure, the pilot valve is pressed up and oil pressure is applied to the upper part of the relief valve.
Because the relief valve opening pressure is exceeded by applying oil pressure to the upper part of the relief valve, the relief valve is pressed down and engine oil flows (oil pressure decrease).
When oil pressure is less than the pilot valve opening pressure, the pilot valve closes. As a result, the relief valve closes and engine oil flow stops (oil pressure increase).
Oil pressure is adjusted by repeating Step (b) to (c).

Oil Pump [Fw6 A EL, Fw6 Ax EL]
Oil Seal (Control Valve Body) Replacement [Fw6 A EL, Fw6 Ax EL]Differential Oil Temperature Sensor Inspection
WARNING:
Hot differential oil may cause severe burns. Do not perform maintenance while
differential oil is hot.
1. Disconnect the negative battery cable.
2. Disconnect the differential oil temperature sensor connector and remove the
differential oil temperature sensor.
3. Wrap ...
Drive Belt Inspection
Generator Drive Belt
NOTE:
The generator drive belt deflection/tension inspection is not necessary with
the adoption of the drive belt auto tensioner.
1. Verify that the indicator part of the cast hexagon on the drive belt auto
tensioner is within the normal range.
If ...
Constant Monitoring
The following components of the air bag systems are monitored by a diagnostic
system:
• Crash sensors, and diagnostic module (SAS
unit)
• Front air bag sensors
• Air bag modules
• Side crash sensors
• Air bag/Front seat belt pretensioner system
warning light
• Fron ...