Engine Code CNNA

Oil Pressure and Switch, Checking

Special tools, testers and auxiliary items required

• Oil Pressure Gauge (V.A.G 1342)

• Adapter for VAG 1342 (V.A.G 1342/14)

• Voltage Tester (V.A.G 1527 B)

• Connector Test Set (V.A.G 1594 C)

• Socket 24 mm and Jointed Extension (T40175)

• For the functional check and servicing of the optical and acoustic oil pressure warning.

Test Conditions

• The engine oil level is OK. Checking, refer to => [ Engine Oil ] Description and Operation.

• The engine oil temperature is at least 80 °C (176 °F) (the fan must start up once).

• The selector lever must be in either the "P" or "N" position.

Oil Pressure Switch, Checking:

- Remove the noise insulation.

- Remove the oil pressure switch and install it in the oil pressure gauge (V.A.G 1342).






- Thread the oil pressure gauge into oil filter housing in place of the oil pressure switch.

• Note the installed position of the adapter: The conical connecting neck on the adapter is screwed to the pressure hose of the gauge.

- Connect the brown wire on the gauge to ground (-).

- Connect the voltage tester (V.A.G 1527 B) to battery positive (B+) (connection in engine compartment - arrow -) and to the oil pressure switch using adapter cables from the connector test set (V.A.G 1594 C). The Light Emitting Diode (LED) must not light up.






If the LED lights up:

- Replace the oil pressure switch.

If the LED does not light up:

• While starting engine, watch the pressure gauge and LED as the switch point of the oil pressure switch may already be exceeded during start up.

- Start the engine and run at idle speed. The LED must light up at 0.7 to 1.1 bar positive pressure, otherwise replace the oil pressure switch.

Oil Pressure, Checking:

- Check the oil pressure at different speeds:

• 1500 RPM: at least 1.7 bar

• 2000 RPM: 3.0 to 5.5 bar

• above 2000 RPM: maximum 7.0 bar

If the specified values are not reached:

- Check the suction pipe strainer for contamination.

- Check the control piston of the oil pressure relief valve for contamination.

- Check the oil pipe on the bottom of the cylinder block for leaks.

• Also, mechanical damage, for example, bearing damage can also be the cause of too low oil pressure.

• The control piston of the oil pressure relief valve is spring loaded. Therefore the highest care is required when removing the plug.

• The plug in the oil pump is tightened to 35 Nm.

If no malfunction can be found:

- Replace the oil pump. Refer to => [ Oil Pump ] Oil Pump.

If the specification is exceeded:

- Check the oil passages.

- Replace the oil pump, if necessary. Refer to => [ Oil Pump ] Oil Pump.