Oil Pressure Switch (For Fuel Pump): Testing and Inspection

Oil Pressure and Oil Pressure Switch, Checking

Special tools, testers and auxiliary items required
^ Oil pressure gauge V.A.G 1342
^ Voltage tester V.A.G 1527 B
^ Connector test set V.A.G 1594C
^ Engine oil level OK.
^ Engine oil temperature at least 80° C (radiator fan must start up once)

Note:
^ Function test and servicing the optical and acoustic oil pressure indicator: wiring diagrams, Function and Component Selection.





- Remove oil pressure switch F1 and install into oil pressure gauge.
- Thread oil pressure gauge into oil filter bracket in place of oil pressure switch.
- Connect brown wire of tester to ground (GND) (-).
- Connect voltage tester V.A.G 1527 B using adapter cables from connector test kit V.A.G 1594C to B+ and oil pressure switch. LED must not light up.
- If LED lights up, replace 1.4 bar oil pressure switch F1.

If the LED does not light up:
- Start engine and increase engine speed: The LED must illuminate at 1.2 to 1.6 bar positive pressure, otherwise replace the oil pressure switch.
- Increase engine speed further. At 2000 RPM and an oil temperature of 80° C, oil pressure must be between 2.7 and 4.5 bar.

At higher engine speeds oil pressure must not exceed 7.0 bar

If the specification is not obtained:
- Check screen in oil intake pipe for contamination.

Note:
^ Also, mechanical damage e.g. bearing damage can also be the cause of too low oil pressure.

If no malfunction can be found:
- Replace oil pump.

If the specification is exceeded:
- Check oil channels.
- If necessary, replace oil filter bracket with pressure relief valve.