Den ene (0,9 bar) sidder ved remhjulet/oliepumpen og den anden (0,3 bar) mellem stødstangsrørene i venstre side.
Her er funktionen sakset fra
http://www.vanagon.com/info/articles/oil-pressure-probs/index.htmMore specifically it works like this:
The dynamic oil pressure monitoring system gets inputs from two pressure switches. One switch is closed with no oil pressure and opens when oil pressure rises to about 0.3 bar, called the .3 bar switch. The .3 bar switch is located between the left (driver's side) two cylinders. The other switch is open with no oil pressure and closes when oil pressure rises to about 0.9 bar, thus called the .9 bar switch. The .9 bar switch is located below the water pump & crank pulley, near the oil pump.
The monitoring system seems to only "look at" the .3 bar switch below 2000 RPM and ignore the .9 bar switch. Above 2000 RPM the active switch is the .9 bar switch while the .3 bar switch is ignored. Below I've described a properly operating monitoring system. Note that I say "monitoring system" because some of the conditions describe an abnormally low oil pressure condition.
A. Ignition ON, engine NOT running -- or -- engine running at LESS than 2000RPM
.9 bar switch is ignored
1. Low oil pressure exists (below .3 bar), keeping .3 bar switch closed
Oil light: Flashes
Buzzer: Silent
2. Normal oil pressure exists (above .3 bar), opening .3 bar switch
Oil light: Off
Buzzer: Silent
B. Engine running at MORE than 2000RPM
.3 bar switch is ignored
1. Low oil pressure exists (below .9 bar), keeping .9 bar switch open
Oil light: Flashes
Buzzer: Sounds
2. Normal oil pressure exists (above .9 bar), closing .9 bar switch
Oil light: Off
Buzzer: Silent