A4 Sedan L4-1.8L Turbo (AEB) (1997)
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Oil Pressure Switch: Testing and Inspection
Oil pressure and oil pressure switch, checking
Function of dynamic oil pressure warning system
Warning lamp, checking
With engine switched off and ignition on (terminal 15 on), oil pressure warning lamp will be lit (not for vehicles with Auto Check system).
Warning criteria
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Engine switched off and oil pressure switch closed.
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Coolant temperature less than 60°C (140°F), engine speed higher than 300 RPM and oil pressure switch open.
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Coolant temperature greater than 60°C (140°F).
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At engine speeds greater than 5000 RPM, an active oil warning won't be erased independent of oil pressure switch setting.
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A Diagnostic Trouble Code (DTC) is recognized when oil pressure switch is open for more than 0.5 seconds at engine speeds greater than 1500
RPM. If condition occurs more than three times during a drive, warning will remain active even at engine speeds less than 1300 RPM.
Special tools and equipment
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VAG1342 oil pressure tester
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VAG1527B voltage tester
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VAG1594A measuring appliance adapter
Test conditions
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Oil level OK
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Oil pressure warning light -K3- must light up when ignition is switched on.
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For vehicles with Auto Check system, 11.011 indicator must be lit (call up symbol)
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Engine oil temperature approximately 80°C (176°F)
Oil pressure switch, checking
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Disconnect line from oil pressure switch.
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Remove oil pressure switch and install VAG1342 oil pressure tester.
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Install oil pressure switch into VAG1342 oil pressure tester.
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Connect brown wire -1- of tester to Ground (G N D).
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Using VAG1594 adapter, connect VAG1 527B voltage tester to oil pressure switch and Battery Positive Voltage (B+).
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LED must not be lit.
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If LED is lit, replace oil pressure switch.
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Start engine.
Note: While starting engine, watch pressure tester and LED as oil pressure switch may open during start.
At 1.2 - 1.6 bar (17.4 - 23.2 psi) LED must be lit.
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If LED does not light, replace oil pressure switch.
Oil pressure, checking
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Disconnect line from oil pressure switch.
