Oil level sensor on m50 sump

Post Sat May 30, 2020 1:41 pm

Hi
The only thing I’ve got to do on my m50 swap is hook up the oil level sensor.
Can anyone point me in the right direction to where I need to pick up the wiring from?
Sorry if it’s been covered before

Post Sat May 30, 2020 1:46 pm

A PM I sent someone many years ago!

50 1/ blue/white (dynamic oil level) E30 2/green/yellow
M50 2/ blue/yellw (static oil level) E30 10/blue
M50 /3 red/white (ABS) E30 20/ red/yellow
M50 4/ black/blue (aircon) E30 not used
M50 5/ black/grey (aircon) E30 not used
M50 6/ purple/grey (aircon) E30 not used
M50 7/ black/purple (drive away) E30 not used
M50 8/ grey (engine check light) E30 12/ grey
M50 9/ NC
M50 10/ NC
M50 11/ brown/yellow (water temp) E30 not used
M50 12/ brown/purple (water temp) E30 4/ brown/purple
M50 13/ green/purple(fuel pump) E30 13/ green/purple
M50 14/ black/white (speed) E30 14/ black/white
M50 15/ black/green ( unloader relays) E30 15/ black/green
M50 16/ white/yellow (Rx data) E30 not used
M50 17/ white purple (Tx data) E30 not used
M50 18/ black/yellow (starter) E30 18/ black/yellow
M50 19/ white/green (service reset) E30 11/ white/green
M50 20/ black (engine speed) E30 9/ black
M50 21/ green (ignition) E30 7 green
M50 22/ green/white E30 6/ green/white
M50 23/ brown/grey (oil pressure) E30 5/ brown/green
M50 24/ white/black (fuel rate) E30 8/ white/black
M50 25/ blue (ignition warning) E30 1/ blue

Hope all this helps (and is not too late)!

Post Sat May 30, 2020 3:31 pm

Thanks Brian

which one is which to clear the oil level light on the onboard computer.
I will need to get a plug for the sensor as my m50 loom didn’t have one as far as know? The only plug I had spare on the loom was a 2 pin for tranny but I’m using g260

Post Sat May 30, 2020 9:25 pm

Not with you? The LED goes off automatically when the oil level is high enough. There's no manual reset, except for the button that stops the 'check' light flashing in the cluster.

Post Sat May 30, 2020 11:47 pm

Hi brian
My m50 engine has the e34 sump with level sensor on but the wiring loom is from a 325i m50 so I don’t have the wiring in place for the sensor in sump?

Post Sun May 31, 2020 12:01 am

Ah, I see. In that case you need to add two wires from the sensor to pins 2 and 10 of the C101.
Wiring diagram doesn't give any pin numbers for the M50 level sensor, so try them both ways and see which works.
I know that the dynamic sensor gives the opposite signal to the static one, so get it the wrong way around and the LED will light when the sump is full, but stay off when it's empty.

Post Sun May 31, 2020 9:15 am

Great cheers brian that’s exactly what I need to know

Post Sun May 31, 2020 9:41 am

It appears that I have already wired these in but god knows where the other ends are as I’ve wired everything as per the below table and was only left with two wires from c101 side. One was a thin solid green that was in same terminal as the thick ecu green. And the other is red/yellow which I think is abs.
So I need to now trace these two wires from pins 2 & 10 and see where the other ends are hiding

.
I knew I should of tested everything before I wrapped the loom

.

This is the table I followed and it was spot on as far as PIN numbers and colours for my engine

9FC44123-0E9A-4166-9B2D-73A6458E5E00.png

This is what I had left over from e30 side just the two mentioned

3934ED02-392B-4880-A2CA-00C6230C88E5.png

And these were what was left over from the m50 side which I’m not worried about as I think these are abs /ac wires.

926AF512-485F-41E8-805E-10A3B3AA9C1F.png

So somewhere in my loom is the offending oil level sensor wires that I need