Checking Dynamic Oil Pressure Warning System (high rpm)The 1.8 bar pressure switch (1.4 bar in diesels) is normally open (no circuit to ground). When the engine is running above 2000 rpm (ignition distributor input to control unit), oil pressure closes the switch (completing the circuit to ground). If oil pressure is insufficient to close the pressure switch, or the switch is stuck open, the indicator will flash and the buzzer will sound. The pressure switch opens and closes at specific pressures. See Testing Oil Pressure Switches. To quick-check the pressure switch, disconnect the yellow wire from the switch and raise the engine speed to between 2000 to 2500 rpm. The indicator should flash and the buzzer should sound. If the wire is connected to ground, the warning should stop. Remove the wire from ground and reconnect to the switch. If the indicator does not go out, replace the switch. |
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