[Blitz513]

Hello! I’m new to the forum and have not found any posts about this particular issue. I recently replaced the OZS sensor on my 2009 BMW 535xi. The car was randomly throwing elevated engine temperature, hot engine, and overheated engine warnings, putting the car into limp mode, and then usually resolving within a few seconds (but not always). On the computer, it looked like the oil temp was spiking during these episodes, but as at least one warning occurred when the vehicle was cold, it seemed to be a sensor problem. Changing the OZS sensor resolved the issue.

This was recently replaced, about 4 weeks ago. Since installation, even though the oil was changed and service interval was reset about two weeks before the OZS sensor was changed, the service monitor has displayed the following message: "Please observe recalculated service interval for engine oil" and at the time of the sensor change, displayed 260 mi remaining on the oil life. That made its way to zero and is now negative, indicating overdue service. I thought I could reset the service monitor as usual, but when I do so, the system ignores the reset attempt and continues to display all of this. Additionally, I do not think the level sensor is actually functioning as it was halfway between min and max when the sensor was installed; I added 1/2 quart and the level did not increase; shortly thereafter, it changed to min (one amber square) but is not advising me to add oil, only to have the system serviced. I added another 1/2 quart very recently with no change.

There are no codes to clear, and there is no apparent way to reset this using a computer and scan tool. Is there a process for initializing or calibrating a new OZS sensor? I have also tried disconnecting and reconnecting the OZS sensor and multiple attempts at performing the oil service reset from the dash.

Thank you!