TL L5-2451cc 2.5L SOHC MFI (1997)
Oil Pressure Warning Lamp/Indicator: Description and Operation
The low oil pressure indicator light works in two ways: it flashes continuously following a momentary loss of engine oil pressure, or it goes ON and stays
ON with a complete loss of engine oil pressure.
When the engine first starts, before its oil pressure rises above 4.3 psi, voltage is applied to the closed and grounded engine oil pressure switch and the
light comes ON to test the bulb.
With the engine running, voltage is applied at the WHT/BLU wire of the integrated control unit. With normal engine oil pressure, the engine oil pressure
switch is open and the low oil pressure indicator light does not come ON. If the engine oil pressure switch closes momentarily (more than 0.5 seconds)
but then opens again, the YEL/RED wire at the integrated control unit will sense ground through the switch. The integrated control unit will then provide
and remove ground for the low oil pressure indicator light through the YEL/RED wire. The light will flash ON and OFF until you turn the ignition switch
OFF. The flashing feature will not work until 30 seconds after initial voltage is applied to the WHT/BLU wire of the oil pressure indicator flasher
circuit. This delay keeps the low oil pressure indicator light from coming ON during engine warm-up.
If engine oil pressure falls below 4.3 psi and does not increase, the engine oil pressure switch will stay closed. The low oil pressure indicator light will
then come ON and stay ON.
