Vanagon 2WD L4-2109cc 2.1L (1986)
Audible Warning Device: Description and Operation
Dynamic Oil Pressure Warning Control Unit
The dynamic oil pressure warning system consist of two pressure switches, the electronic control unit, the low oil pressure indicator, and the warning
buzzer. One switch provides the electronic control unit warning information when the oil pressure falls below 4.4 PSI at any RPM range including engine
idle. The other switch provides the electronic control unit warning information when the oil pressure falls below 13.1 PSI at cruise RPM. One oil
pressure switch is located on the drivers side of the engine (4.4 PSI), and the other is located on the front of the engine near the oil pump (13.1 PSI). The
electronic control unit is located behind the instrument cluster.
The 4.4 PSI oil pressure switch completes a circuit to ground with the engine switch off. When the ignition switch is turned on, no oil pressure is
indicated by the flashing indicator. When the engine is started and oil pressure rises, the switch opens the circuit to ground, and the indicator goes out.
The 13.1 PSI oil pressure switch normally is an open circuit to ground. When engine RPM rises above 2000 RPM oil pressure causes the switch to
complete the ground circuit. If the oil pressure is insufficient the ground circuit will not be completed causing the warning indicator to flash, and the
buzzer to sound.
