Oil Pressure Sender: Testing and Inspection

Oil pressure and oil pressure switch, checking





Special tools and equipment
^ 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 when there is no pressure and closes when the specified switch pressure is reached.
The oil pressure warning 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 instrument cluster must light up for approx. 3 seconds and go out again afterward. 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 to 3 seconds, this is stored in the combi-processor of the instrument cluster. If this condition happens three times while the engine is running, the oil pressure warning is immediately triggered and remains on, even below 1500 rpm. The oil pressure warning goes out when the oil pressure switch is closed for longer than 5 seconds when the engine revolutions are greater than 1500 rpm or ignition is "switched off".

Requirements
^ Engine oil level OK

Engine code BBW
^ Oil pressure warning light -K3- must light up for approx. 3 seconds when ignition is switched on

Continued for all engines
^ Coolant temperature minimum °C (coolant fan must run once)

Note: Functional check and servicing the optical and acoustic oil pressure warning.

Work sequence





- Remove Oil pressure switch -F1- and screw into tester.
- Screw tester into oil filter bracket in place of oil pressure switch.
- Connect brown wire of tester to Ground (-).
- Connect diode test lamp V.A.G 1527 B using auxiliary cables from V.A.G 1594 A to battery positive (+) and oil pressure switch.

LED must not light up.
If the LED lights up:
- Replace 1.4 bar oil pressure switch -F1-.

If the LED does not light up:
- Start engine and increase revolutions slowly.

At 1.2 to 1.6 bar pressure LED must light up

If the LED does not light up:
- Replace oil pressure switch.
- Increase engine speed further.

At 2000 rpm and an oil temperature of 80°C oil pressure should be between 2.7 to 4.5 bar

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

If the specifications are not attained:
- Correct mechanical damage, e.g. bearing damage.
- Replace oil filter bracket with pressure relief valve or oil pump.

If the specification is exceeded:
- Check oil galleries.
- If necessary, replace oil filter bracket with pressure relief valve.