Oil pressure and oil pressure switch, checking

WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Special Tools - Oil Pressure And Oil Pressure Switch, Checking

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Special tools and equipment

VAG1342 Oil pressure gauge
VAG1527B Voltage tester
VAG1594A Connector test kit

Requirements

Oil level OK
Engine oil temperature approximately 80 C.
With ignition on, Oil pressure warning light -K3- must be lit.
For vehicles with Auto Check System, "OK" indicator must be lit (call up symbol).

Oil pressure switch, checking

Fig 2: Identifying Exhaust Pipe Fasteners

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For vehicles with auxiliary heater, remove bolts (arrows) for exhaust pipe of auxiliary heater on sound insulation.

Fig 3: Identifying Quick-Release Fasteners And Noise Insulation

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Remove bolts or quick-release screws -1- and -2- and remove front sound insulation.

Fig 4: Disconnecting Electrical Harness Connector At Oil Pressure Switch

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Disconnect electrical harness connector at oil pressure switch (arrow).

Fig 5: Removing Oil Pressure Switch And Installing VAG1342 Oil Pressure Tester

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Remove oil pressure switch and install VAG1342 oil pressure tester.
Install oil pressure switch -2- on VAG 1342.
Connect brown wire -1- of tester to ground (GND).
Using VAG1594A connector test kit, connect VAG1527B voltage tester to oil pressure switch and Battery positive (+).

LED must not be lit

If LED is lit:

Replace oil pressure switch.
Start engine.

NOTE: While starting engine, watch pressure tester and LED as oil pressure switch may open during start.

Black oil pressure switch

At 1.2 to 1.6 bar pressure, LED must light up

If LED does not light up:

Replace oil pressure switch.

Oil pressure, checking

Disconnect electrical wire from oil pressure switch.

Fig 6: Removing Oil Pressure Switch And Installing VAG1342 Oil Pressure Tester

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Remove oil pressure switch and install VAG1342 oil pressure tester.
Install oil pressure switch -2- on VAG 1342.
Start engine (engine oil temperature approximately 80°C).

Oil pressure at idle: at least 1.5 bar
Oil pressure at 2000 RPM: at least 3.0 bar

If specified values are not obtained:

Pressure relief valve or oil pump faulty, replace oil pump.