88 M6 Oil Sensor not reading on alert screen?

[M6SCOTT]

Just had a new oil sensor installed on my 1988 M6 with 60,000 miles. The mechanic cannot get it to read to the onboard a alert screen to the left of the steering wheel? Is it the sensor? Is it the wiring from the sensor to the screen? really don't want to keep having to check my oil by the dipstick because the mechanic is having trouble getting it to read out on the screen where it's supposed to read out?

[carsnplanes]

Just had a new oil sensor installed on my 1988 M6 with 60,000 miles. The mechanic cannot get it to read to the onboard a alert screen to the left of the steering wheel? Is it the sensor? Is it the wiring from the sensor to the screen? really don't want to keep having to check my oil by the dipstick because the mechanic is having trouble getting it to read out on the screen where it's supposed to read out?
"Oil Level" light on the check panel is for low oil level only, not for monitoring proper level. That's what the dipstick is for. If the light comes on, you are well below the Low line on the dipstick. Sensor is mounted on the bottom of the oil pan.
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[jbd5015]

After looking at a wiring diagram, which a mechanic with reasonable resources should be able to find, Im guessing its a ground problem. That is based on the sensor being in functional condition (ie just replaced).

There are actually 2 switches inside the sensor. A "static" and a "dynamic" switch. According to the wiring diagram I am looking at, the switches are grounded to the case in the M6. It may or may not be different in the case of the 635's. This would be confirmed by noting there would only be 2 wires running to the sensor. Those wires run to the check control panel. They are noted as being Blue/Violet for Static Switch, and Blue/White for Dynamic Switch. Grounding is done via the case of the sensor. Must make sure the mounting area is clean as a whistle! Perhaps if the ground is the culprit, one could test the theory by running a new ground from one of the mounting bolts to a KNOWN GOOD GROUND.

If there are 3 wires running to the sensor (apparently unlikely for the M6), the third wire would be a ground. This ground wire is being noted at ground (G103), which i cannot locate, but would likely be near by!

All this could be a possible solution. Not sure how the sensor gets "filled" with oil. Potential blockage inside the pan preventing the sensor from actually being filled with oil? Pretty unlikely I would imagine. These cars werent really prone to sludge issues with regular service.

Good luck! Id spend some time with a voltmeter on this one.

[e24mpwr]

I have check-lights on oil and coolant (and both are at fine levels). Need to do some debug on this at some point...

[RSheiman]

I recall sensor having a float inside which can get hung up.