[XanderPace]

Hi guys, I'm having an issue with my 2010 i30 FD 1.6 CRDI. The amber oil level warning light has come on recently. First thing I did was check the level on the dipstick and that was good and there was no evidence of a leak. My annual oil and filter change was due anyway, so after reading through another post on the the forum I assumed it would be the oil level sensor so ordered one and changed it out at the same time as the oil. The light is still lit, after reading through the user manual I found out you can turn the light out by flicking the key between off and run 3 times however the light comes back on every 30 miles. I've tried to use an OBD2 scan tool to clear the ECU but it came back with no codes stored. I'm not overly concerned about it as I know the oil isn't low but I'm thinking of upgrading soon and would like there to be no lights on the dash when I sell. I'm thinking it could be a short in the wiring, does anyone know how I could confirm this and help find it.

[The Gonz]

You seem to have covered all the sensible things.
If you're looking for a possible short, consider the part of the sensor that has not been changed, namely the loom that carries the signal back to the BCM/ECU.

[XanderPace]

I've checked wiring as best I can physically and can't see any damage and I've used a multimeter. There is continuity between the earth terminal on the plug and the negative battery terminal, the power terminal and the positive at the battery and the signal and the ECU. The ground and the chassis reads 0V, and the power and chassis and signal and chassis both 12V. The strange reading I'm getting is with the ignition off there's 120 ohms between the power and ECU and -160 ohms between the ground and ECU when they both should be 0. So I'm a bit confused as to what the issue is.

[The Gonz]

-160 ohms is not possible. The ohmmeter mode of your multimeter generates a small current of its own to measure resistance. If you're seeing a negative resistance, it means you've got a current flowing with the ignition off, which is not surprising given alarm and other sleep modes. You'd have to disconnect the battery to get good resistance readings in that particular instance.