Oil Pressure Sender: Testing and Inspection

Oil pressure and oil pressure switch, checking

Special tools and equipment





^ VAG1342 Oil pressure tester
^ VAG1527B Diode test lamp
^ VAG1594A Adapter set

Function of dynamic oil pressure warning system
The oil pressure switch is open at no pressure and closes when switch pressure is reached.
The oil pressure is activated approximately 10 seconds after switching ignition on ("terminal 15 on").
Switch-on delay of oil pressure warning: Approximately 3 seconds
Switch off delay for oil pressure warning: Approximately 5 seconds

Checking warning lamp
After switching on ignition when engine is not running, oil pressure warning lamp in instrument cluster must light up for approximately 3 seconds and go out again afterward. The test will be terminated if engine is running.

Criteria for warning
Switching on of optical oil pressure warning (oil pressure warning lamp flashes) and the buzzer sounding three times for acoustical warning will occur under one of the following conditions:
^ "Ignition on", engine at rest, oil pressure switch closed
^ Engine speed higher than 1500 rpm, oil pressure switch open
^ At engine revolutions greater than 5000 rpm the oil pressure warning will not be triggered, even when the oil pressure switch is closed.
^ If the oil pressure switch is open (engine revs greater than 1500 rpm) for 0.5 to 3 seconds, this is stored in the combi processor of instrument cluster. If this condition happens three times while the engine is running, the oil pressure warning is immediately triggered and remains on, even below 1500 rpm. Oil pressure warning goes out when oil pressure switch is closed for longer than 5 seconds when engine revolutions are greater than 1500 rpm or ignition is "switched off".

Requirements
^ Oil pressure warning light -K3- must light up for approximately 3 seconds when ignition is switched on.
^ Engine oil temperature at least 80°C(coolant fan must have run once).

Work sequence





^ Remove Oil pressure switch -F1- and install in tester.
^ Thread tester into oil filter bracket in place of oil pressure switch.
^ Connect brown tester wire to Ground (GND).
^ Connect diode test lamp VAG1527B using aux. cables from VAG1594A to battery positive (+) and oil pressure switch.
LED must not light up

If LED lights up:
^ Replace 0.7 bar Oil pressure switch -F1-.
If LED does not light up:
^ Start engine and increase speed slowly. At 0.55 to 0.85 bar pressure:
LED must light up
If LED does not light up:
^ Replace oil pressure switch.
^ Increase engine speed further.
At 2000 rpm and an oil temperature of 80°C oil pressure should be at least 2.0 bar.
At higher engine speeds oil pressure must not exceed 7.0 bar
If specifications are not obtained:
^ Mechanical damage possible, e.g. repair bearing damage.
^ Replace oil filter bracket with pressure relief valve.
If the specification is exceeded:
^ Check oil galleries.
^ If necessary, replace oil filter bracket with pressure relief valve