I have a Mariner 150Hp EFI W/ direct injection. My "High heat / Low oil" Sensor activates approx. 5 seconds after starting a cold engine with plenty of oil in the reserve tank (where the low oil sensor is located). I 've thoroughly tested both the temp. sensor(in the powerhead) and the oil sensor(using an ohm meter to verify an open circuit during normal conditions and a closed circuit under simulated conditions)and both seem to function normally.
