Oil pressure light flashes in display, but oil pressure is ok, even new sensor
 

Hi Everybody,
I have a problem with my Audi A4 B6 1.6 from 2003, in the large middle display I have a warning: Oil pressure with big letters and a blinking image of an oil can above it. It starts when the ignition is turned on and I drive away and won't stop until I turn off the ignition. The car has been to a Audi specialist garage who has measured the oli pressure ( was ok, at 4 bar ), made a reading from the boardcomputer ( nothing reported ), replaced a piece of wireing ( there was a doubt if the malfunction could be in there ), and placed a brand new oil pressure sensor. Also all the wireing between the boardcomputer and the display in the dash was tested, no problem found there. Still the warning won't go away, it comes back every time I use the car accompanied with three annoying beeps. According to the mechanic the motherboard at the back of the display ( could ) be the one that's defective, but can't tell for sure. This "repair" has cost me REALLY a lot of cash until now, and the problem is still not gone away. Does anyone on this forum dealed with this problem ( or something close like this ) before and possibly know of any solution? I really rather know for sure before I throw any more cash at it, and replace the whole dash unit.
thanks in advance,
greetings Finnie

I don't want to insult your intelligence, but have you checked the oil level?

That was the first thing I checked, even before bringing the car to the garage, the oil level was and is as specified.

i had the same problem after i got an oil change. they didn't use audi spec oil. i replaced it with castrol syntec 5w30 and the problem went away immediately.