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

Oil Pressure and Pressure Switch, Checking

Special tools, testers and auxiliary items required
^ Oil Pressure Gauge V.A.G 1342
^ Voltage Tester V.A.G 1527B
^ Connector Test Set V.A.G 1594C

Requirements
^ 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".

Test Sequence





- Remove oil pressure switch F1 and screw 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.
- Connect voltage tester V.A.G 1527B 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 LED does not light up:
- Start engine and increase engine speed: LED must light up at 1.2 to 1.6 bar positive pressure, otherwise replace oil pressure switch.
- Increase engine speed further. At 2000 rpm and an oil temperature of 80° C, the oil pressure should be between 2.7 to 4.5 bar.

At higher engine speeds oil pressure must not exceed 7.0 bar

If 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 specification is exceeded:
- Check oil channels.