Automatic Oil Measuring function

I have owned my 2002 911 Cabriolet 4 years. I am sometimes bedeviled by the automatic oil measuring function performed by the computer as I am starting the car. I have never been able to determine any pattern. I understand it can be triggered by turning the key to "on" and pausing (without turning it all the way to "start"). That is sometimes true, but conversely, turning the key through "on" to "start" in one motion does not prevent the oil screen from appearing (and preventing the car from starting). Sometimes I do not see the screen for weeks at a time; other times it comes up about half the times I turn the key. When it is misbehaving; If I cancel it with the computer operating lever, it simply reappears when I cycle the key. If I allow it to run its course, it simply reappears when I cycle the key to try starting again. Today I sat in a parking lot attempting about 40 times to get past the screen and start the car. I tried every combination of actions I could think of -including those that had worked in the past - to no avail. (I have tried removing the key; or not removing it. I have tried taking my feet off the clutch and brake, or not. I have tried it while in gear, or in neutral.) Then on one attempt it started. I have another car I drive that has a totally different clutch feel, so I have sometimes choked off this car while hurriedly pulling into traffic at an intersection. That inevitably triggers this measuring function, so the heavy traffic needs to flow around me as I try to get past this. It is very dangerous and my wife refused for a long time to get in the car with me, and she refuses to even attempt to drive it. So until I can get this fixed, having the car is not nearly as much fun as it should be. I wonder if the computer needs to be reprogrammed? I have read there is no way to permanently disable this function.

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That's a undesirable dilemma, for sure. Hopefully someone on Carpokes will have some ideas. Maybe just a defective sensor or a bad connection or ground? Meanwhile (and especially if no suggestions from others), I'd be at the front doorstep of a good Porsche shop or quality Porsche dealership. That's a potentially dangerous situation if not simply an inconvenient one were you to get stranded.

Yeah, what Blueline said! This is not good behavior from your car. The oil sender should never keep you from starting and driving the car. This function has nothing to do with starting and driving and you seriously need to get it checked out. IMO, this oil level feature simply cannot be relied upon. Your dipstick is the best way to gauge oil level (cold engine). I have a 3.6 997 and all of the 997's did not come with a dipstick. The 3.6 has a blank in the block where a dipstick should go so I added a dipstick to my car. Could not be happier, as the oil level sender had failed and it would always read full - even when empty. The 3.8 "S" has no such blank in the block and so no dipstick can be added to the 3.8. I realize the 996 is different from the 997, but I still am not convinced that any electronic oil level readings can be totally reliable...and they certainly should not interfere with starting or driving safely. Would love to learn what you discover on this!

That sounds more like an intermittent input/starting issue than something that simply needs reprogramming. On the early 996s, the oil-level display can come up after a start attempt that the car sees as an interrupted/failed start, so the fact that it happens after stalling makes me suspicious of the clutch/start interlock or ignition switch rather than the oil-level system itself. Since you were able to try it 40 times and then suddenly have it start normally, I’d have the shop scan the DME and instrument cluster for stored faults and specifically check the clutch pedal switch, ignition switch, and starting authorization circuit. I wouldn’t try to disable the oil measurement function it’s useful, and the underlying intermittent signal is what needs fixing. Given how unpredictable it is in traffic, I’d definitely get the electrical/start circuit diagnosed before continuing to drive it regularly. A bad ignition switch or clutch switch would fit the intermittent nature much better than a software programming issue. Would you rather start with the clutch switch or have the shop scan the car first?

What Sprinter said! I had a problem where the car would decide not to start on occasion, and fixing (or bypassing) the clutch interlock fixed it. You can fashoin a bypass jumper cable with a 6" piece of wire and a couple of spade connectors (both male or both female, I forget which) and install it in ten minutes. That will at least eliminate a common cause of intermittent start problems. I know this doesn't jibe perfectly with your description, but it may be worth a try. Good luck!