Checking oil pressure switch

WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, and 2003 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect wire from oil pressure switch.

Fig 1: Connecting Oil Pressure Tester V.A.G 1342 With Adapter V.A.G 1342/14 To Bore For Oil Pressure Switch

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Remove oil pressure switch and screw into oil pressure tester VAG1342.
Screw oil pressure switch - 2 - into VAG1342.
Connect brown wire - 1 - of tester to Ground (-).
Connect voltage tester VAG1527B to oil pressure switch and positive terminal of battery (+) using test leads from VAG1594A.

LED should not light up

If LED lights up:

Replace oil pressure switch.
Start engine.

NOTE:

Switching point of oil pressure switch can be reached when engine is cranked on starter motor, so watch tester and LED while starting engine.

Black oil pressure switch

LED should light up at 1.2 to 1.6 bar

If LED does not light up:

Replace oil pressure switch.