2005 Audi A4 2.0T oil sensor warning

Check the coolant first. Add as needed. Once full. heat it up in the driveway and check for leaks. 3.4 montana, I would guess the water pump. Change the T stat also.

It is a low oil warning I would guess.

Good.

The yellow light oil sensor on Audi TT Quattro is the warning message for the minimum oil level has been reached !!!
Check engine oil level by dipstick & fill up oil inside engine !!!

My 2005 A4 3.0 convertible audi is not a diesel, but I had a similar experience with a low oil signal going on and after checking the oil, which was sufficient, and replacing the dipstick, the light did not come back on until a subsequent trip. The light usualIy went on when I was close to the needing an oil change. I've had the car, a used one, for about two years, and the oil light minimum signal started behaving like yours early. About a week ago the oil pressure warning light came on. I don't know if there's a relationship, but if there is be careful. Audis of our vintage have a problem with sludge build up that damages the oil pump, which is a costly item. If you drive the car with low oil pressure you may seriously/fatally damage the car. I don't know if the sludge, if that's what you have, can be cleaned out, but I'd do it if it can be. My mechanic advised me to trade the car to a dealer rather than fix it. Hope you have better luck!

Pontiac Montana, 2005
With the ignition key in RUN but engine off, repeatedly push the trip reset button until OIL is displayed on the driver info center. Once OIL is displayed, push and hold the reset button for five seconds. The number will disappear and be replaced by 100% of oil life remaining. The percentage will return to 100 and oil life indicator will be reset. Repeat steps if not reset to 100.
Good luck

A vehicle's Emission Control Light is a generalized indicator that there is fault or possible malfunction in the vehicle's operating system. In some cases, these warning lights will come on if a gas cap is not fully closed. It could any one of a number of sensors such as the o2 sensor or map sensor. The thing to do is have a reputable mechanic/technician run a diagnostics test on the vehicle.

Turn key to the on position and press the gas pedal to the floor 3 times.then turn key back off then start it if it blinks at you 3 to 4 times real fast its reset..

most cars have a self diagnosis proceedure during and just after startup. this is not a fault unless it appears while going round corners or just generally driving around. you have had the sense to check your levels and pressures then i wouldnt worry too much about it unless it stays on or is as i say on while driving.

Usually it Means that you are low on Oil or Coolant.