Volkswagen Workshop Service and Repair Manuals

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ V.A.G 1342 Oil pressure tester
• ◆ V.A.G 1527 B Diode test lamp
• ◆ V.A.G 1594 A Adapter set

Function of the dynamic oil pressure warning system

The oil pressure switch is open at no pressure and closes when the switch pressure is reached.

The oil pressure is activated approx. 10 seconds after switching the ignition on ("terminal 15 on").

Switch on delay for oil pressure warning: approx. 3 seconds

Switch off delay for oil pressure warning: approx. 5 seconds

Checking warning lamp

After switching on the ignition when the engine is not running, the oil pressure warning lamp in the dash panel insert must light up for approx. 3 seconds and go out again afterwards. The check is terminated if the engine is running.

Criteria for warning

The optical oil pressure warning switches on (the oil pressure warning lamp flashes) and the buzzer sounds three times for audible warning 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 an engine speed greater than 5000 rpm the oil pressure warning is not erased; even when the oil pressure switch is closed. Oil pressure warning goes out below 5000 rpm.
• ‒ If the oil pressure switch is open (engine revs greater than 1500) for 0.5 ... 3 seconds, this is stored in the combi-processor of the dash panel insert. If this condition happens three times whilst the engine is running, the oil pressure warning is immediately triggered and remains on, even below 1500 rpm. Oil pressure warning goes out when the oil pressure switch is closed for longer than 5 seconds when engine revolutions are greater than 1500 rpm or ignition is "switched off".

Test prerequisites

• ● Engine oil level OK, checking , fig. 1
• ● Oil pressure warning lamp (K3) must light up for approx. 3 seconds when ignition is switched on
• ● Coolant temperature minimum 80 °C (radiator fan must run once)

Test sequence

• ‒ → Remove oil pressure switch (F1) and screw into tester.
• ‒ Screw tester into the oil filter bracket in place of the oil pressure switch.
• ‒ Connect brown wire of tester to earth (-).
• ‒ Connect diode test lamp V.A.G 1527 B using aux. cables from V.A.G 1594 A to battery positive (+) and oil pressure switch.
      LED must not light up.
• ‒ If the LED lights up, renew 1.4 bar oil pressure switch (F1).

If the LED does not light up:

• ‒ Start engine and increase revolutions slowly. At
      1.2...1.6 bar pressure
  LED must light up, 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... 4.5 bar

At higher engine speeds the oil pressure must not exceed
    7.0 bar.

If the specifications are not attained:

• ‒ Rectify mechanical damage, e.g. bearing damage.
• ‒ Renew oil filter bracket with pressure relief valve => page 17-9, item 13 or oil pump.

If the specification is exceeded:

• ‒ Check oil galleries.
• ‒ If necessary, replace oil filter bracket with pressure relief valve
  => Page 17-9, item 13