Audi Workshop Service and Repair Manuals

Function of dynamic oil pressure warning system

Testing warning lamp

The oil pressure warning lamp lights up when the ignition is switched on ("terminal 15 on") with the engine not running (this does not apply to vehicles with auto-check system).

Conditions for activation of warning

• ● Engine not running; oil pressure switch closed.
• ● Coolant temperature below 60°C, engine rpm above 300 rpm and oil pressure switch open.
• ● Coolant temperature above 60°C, engine speed above 1500 rpm and oil pressure switch open.
• ● When engine speed is above 5000 rpm an active oil pressure warning is not cancelled, irrespective of the condition of the oil pressure switch.
• ● If the oil pressure switch is open for longer than 0.5 seconds at engine speeds above 1500 rpm, this condition is stored in the memory. If this condition occurs three times during one journey, the warning will also become active or remain active at engine speeds below 1300 rpm.

Special tools, testers and auxiliary items

• ◆ Oil pressure tester V.A.G 1342
• ◆ Voltage tester V.A.G 1527 B
• ◆ Adapter set V.A.G 1594 A

Requirements for test:

• ● Oil level ok.
• ● Oil pressure warning lamp -K3 must come on when ignition is switched on.
• ● In vehicles with auto-check system the "OK" display must appear (call up symbol).
• ● Engine oil temperature approx. 80 °C

Testing oil pressure switch

• ‒ Disconnect wire from oil pressure switch.
• ‒ → Unscrew oil pressure switch and screw in oil pressure tester V.A.G 1342.
• ‒ Screw oil pressure switch -2- intoV.A.G 1342.
• ‒ Connect brown wire -1- of tester to earth (-).

• ‒ Connect voltage tester V.A.G 1527 to oil pressure switch and positive side of battery (+) using test leads from V.A.G 1594.
• ‒ Test lamp should not light up
• ‒ If test lamp lights up, renew oil pressure switch.
• ‒ Start engine

Note:

The switching point of the oil pressure switch can be reached when the engine is cranked on the starter motor, so watch the tester and the test lamp while starting the engine.

• ‒ Test lamp should light up at 1.2...1.6 bar.
• If test lamp does not light up, renew oil pressure switch.

Testing oil pressure

• ‒ Disconnect wire from oil pressure switch.

• ‒ → Unscrew oil pressure switch and screw in oil pressure tester V.A.G 1342.
• ‒ Screw oil pressure switch -2- intoV.A.G 1342.
• ‒ Start engine (engine oil temperature at least 80°C).
• ‒ Oil pressure at idling speed: 1.0 ... 3.5 bar
• ‒ Oil pressure at 3000 rpm: 5.0 ... 7.0 bar

If the specifications are not obtained:

• ‒ Pressure relief valve or oil pump defective; renew oil pump .