Operation Timing; Ignition Switch Off Function; Oil Pressure Control Outline [13B-Msp]; Oil Pressure Control Block Diagram [13B-Msp] - Mazda RX-8 2009 Service Highlights

Operation timing

The PCM calculates the oil level required by the engine according to the engine operation conditions. When the
calculated value reaches the discharge amount, a drive signal is sent to the metering oil pump driver and the
metering oil pump operates (ON/OFF) to discharge oil.
Demand-oil amount
— The demand-oil amount is determined for metering oil pumps No.1 and No.2 respectively.
— The base flow amount, based on engine speed and engine load, is compared with the minimum flow
amount, based on the engine coolant temperature and intake air temperature, and the larger of the two
values is selected as the demand-oil amount.
Discharge amount
— The discharge amount is the oil amount injected from the center oil nozzle and side oil nozzles when
metering oil pump No.1 or No.2 operates once.
— The discharge amount is corrected according to battery positive voltage, the metering oil pump internal
pressure, and engine coolant temperature.

Ignition switch off function

Engine startability at cold temperatures is improved by discharging engine oil while the ignition is switched off.
If the engine is started with the coolant temperature lower than 20 C {68 F} and the ignition is switched off
with the coolant temperature lower than 60 C {140 F}, the PCM calculates the necessary oil amount based on
the coolant temperature. The PCM controls the metering oil pump driver until the engine rotation is completely
stopped.
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OIL PRESSURE CONTROL OUTLINE [13B-MSP]

The amount of oil supplied to the metering oil pump is adjusted based on the engine operation conditions to
keep the oil pressure inside the metering oil pump constant.
Based on the input signals from the oil pressure sensor, the PCM drives the OCV and switches the oil
passages of the metering oil pump so that the oil pressure inside the metering oil pump is kept constant.
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OIL PRESSURE CONTROL BLOCK DIAGRAM [13B-MSP]

OIL PRESSURE SENSOR
ECT SENSOR
BATTERY
ECCENTRIC SHAFT
POSITION SENSOR
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OIL PRESSURE CONTROL OPERATION [13B-MSP]

Operation

The PCM divides the oil control valve drive range into four modes according to the engine operation conditions
and controls the target current for each control zone.
Engine start mode
This mode opens the passage between the OCV and metering oil pump to feed oil into the metering oil pump at
an early stage. After oil-feed into the metering oil pump is detected based on the input signals from the oil
pressure sensor, the mode changes to the feedback mode.
Feedback mode
The PCM controls the OCV target current so that the actual oil pressure in the metering oil pump is close to the
target value determined according to the engine operation conditions.
CONTROL SYSTEM [13B-MSP]
PCM
01-40
id0140g1304600
id0140g1304700
OCV
ar8uun00000365
id0140g1304800
01-40–21