Some 2009-2011 Audi models may display a low oil warning, but the problem may be due to a faulty hood contact switch. This applies to 2009-2011 A4, S4 and Q5 models, 2008-2011 A5, S5 Coupe models and 2010-2011 A5 and S5 cabriolet models.
The hood must be open for at least 30 seconds for a reset of this message to be performed. The message is not reset in the DIS/MMI because the hood has not been recognized as being opened due to an inoperative hood contact switch.
Improved hood contact switches have been out into current production vehicles, and a software change with improved logic is planned for production.
Check the hood contact switch. Use the VAS diagnostic tester to read MVB 26 in the J393 – Comfort System Control Module (address code 46) after the hood is opened and closed.
If the value does not change, then replace only the contact switch. Do not replace the complete hood latch assembly. Replace only the micro-switch.
There are two suppliers for B8 hood latches. Check the part number on the current contact switch connector to determine which part number must be ordered (8T0 953 236 or 8K0 953 236).
The two suppliers use different designs for the contact switch, so the mounting location is slightly different on the different hood latches. The contact switches are not cross compatible between the different latches. However, the latches can be swapped between vehicles as long as the correct contact switch is installed.
If the value in the MVB changes as expected (normal operation of the contact switch), then the vehicle may have an oil issue. Check the oil according to the instructions in the Repair Manual.