Oil warning light

[zkd]

I have the high cluster on my e34 touring, the Oil Warning light should come on when I put the ignition in position 2 without starting the car if I remember correct. but it doesn't. so I checked the voltage on the connector and it give about 0.5v when the key is in position 2 but when it's in position one it's almost 0. I checked the bulb and it is fine. (it is connected on pin 6 of the yellow connector x16, wire is Brown/Green)

what could be wrong and how to fix it please.

[Mixzzz]

It could be faulty wiring to the oil pressure sensor or maybe stuck oil pressure sensor itself but I'd say it's the wiring

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[funfunfer]

I had a similar oil pressure warning light issue on my '91 M5. Replaced the sensor twice, then installed an adapter for an analog Oil Pressure test gauge. Pressures on the gauge were spot on 30-75 psi. Upon removing the gauge, my pressure warning light issue ended. My guess is that over 240,000 miles there was a build up of crud in the passage going to the OP sender. I've retained the adapter and have installed VDO electronic oil pressure and temperature gauges just below the HVAC control head.

[moroza]

I checked the voltage on the connector

Which connector, the one to the oil pressure sender? It shouldn't get 12V because the connector is in series with the bulb, which causes a voltage drop. Try grounding the brown/grey wire and see if the bulb turns on. The other wire on the OP sensor connector should be directly grounded. If not, the wiring is bad somewhere. The BR/GR wire goes through splice X8010 somewhere in the engine harness, then through the big round connector X20 at pin 23. It's brown/grey on the engine side (but you have an M52 so it might be different) and brown/green on the body side. From there it's a straight wire to pin 6 of connector X16 ("natural" colored, that is, beige) on the instrument cluster, where all it does is ground the oilpressure light bulb.

[zkd]

Which connector, the one to the oil pressure sender? It shouldn't get 12V because the connector is in series with the bulb, which causes a voltage drop. Try grounding the brown/grey wire and see if the bulb turns on. The other wire on the OP sensor connector should be directly grounded. If not, the wiring is bad somewhere. The BR/GR wire goes through splice X8010 somewhere in the engine harness, then through the big round connector X20 at pin 23. It's brown/grey on the engine side (but you have an M52 so it might be different) and brown/green on the body side. From there it's a straight wire to pin 6 of connector X16 ("natural" colored, that is, beige) on the instrument cluster, where all it does is ground the oilpressure light bulb.

the connector I checked is x16 which the yellow next to the brown on the instrument cluster. the brown/green is the wire going to Pin 6. from the electrical diagram you are right it should ground when oil pressure is low. no voltage should be on there. my mistake..

I will ground the wire and see what happens then I will check x20 connector and see if there is a problem there, then I will check the pressure switch and see if there is a problem there.

[shady13]

the connector I checked is x16 which the yellow next to the brown on the instrument cluster. the brown/green is the wire going to Pin 6. from the electrical diagram you are right it should ground when oil pressure is low. no voltage should be on there. my mistake..

I will ground the wire and see what happens then I will check x20 connector and see if there is a problem there, then I will check the pressure switch and see if there is a problem there.

Hi! Have you managed to solve the problem with the oil warning light? I have the same issue now and wonder what can cause it…