If MSD detects, that the oil supply system is not able to maintain required pressure (it means, the pressure value does not correspond to a required value longer than time X, or PWM value for time Y is not within required values), MSD turns on the emergency oils supply mode.
1. Pressure relief valve is completely closed, it can be seen here: ../F6/F2/F3. PWM is decreased to 0%, it means, even the valve connection is not controlled:
2. Pressure control module ../F6/F2/F2 reports, that required pressure is 0 hPa, but MSD continues to report maintained pressure. As we can see, (even) in idle the oil pressure reach around 5800 hPa (+1000 hPa has to be added to value displayed). Such pressure (5800 .. 6200 hPa) is maintained in all range of engine’s RPM.
Similar strategies are used by MSD, for example, in case of LPFP problems – PWM of the pump is increased to 100% (it means, full voltage is supplied to the pump), and the pump pressure reaches around 8 bar.