Oil level doesn't matter; it's how long since the last reset. It is designed to be reset manually at each oil change. 4500 miles later it will flash on startup, and then at 5000 miles it stays on. Reset instructions are in the owner's manual.
If it is in the manual I have not found the right item. Do you know what it is listed under? Rsuetterlin
I had to reset the light myself a couple of weeks ago because my mechanic forgot to do it. This is from the 2007 owners manual ("Service reminder indicators and warning buzzers" section), but I think it should be the same for 2009: The system must be reset after the engine oil replacement. Reset the system by the following procedure: 1. Press the “POWER†switch to the “OFF†mode with the odometer reading shown. 2. Press the “POWER†switch twice to select the “IG-ON†mode while holding down the trip meter reset button. Hold down the button for at least 5 seconds. The odometer indicates “000000†and the light goes off. If the system fails to reset, the light will remain flashing.
