Safe Mode
 

Could somebody tell me what this is? Also, why would it affect the Porsche from starting?

Hi,

You're more likely to get answers to questions if you post a bit more information about your question and also about your vehicle.

As is, I have no clue what "safe mode" might be or what it relates to. Give us a bit more info and I'm sure you'll get an answer....

I have no clue...but Bill Gates might know! I get this warning sometimes on my laptop! :) I second Denverpete's advice...we need more info.

Bill Gates
 

At a recent computer expo (COMDEX), Bill Gates reportedly compared the computer industry with the auto industry and stated, "If GM had kept up with technology like the computer industry has, we would all be driving $25.00 cars that got 1,000 miles to the gallon."


In response to Bill's comments, General Motors issued a press release stating: If GM had developed technology like Microsoft, we would all be driving cars with the following characteristics (and I just love this part):

1. For no reason whatsoever, your car would crash twice a day.

2. Every time they repainted the lines in the road, you would have to buy a new car.

3.. Occasionally your car would die on the freeway for no reason. You would have to pull to the side of the road, close all of the windows, shut off the car, restart it, and reopen the windows before you could continue. For some reason you would simply accept this.

4. Occasionally, executing a maneuver such as a left turn would cause your car to shut down and refuse to restart, in which case you would have to reinstall the engine.

5. Macintosh would make a car that was powered by the sun, was reliable, five times as fast and twice as easy to



drive -- but would run on only five percent of the roads.

6. The oil, water temperature, and alternator warning lights would all be replaced by a single "This Car Has Performed An Illegal Operation" warning light.

7. The airbag system would ask "Are you sure?" before deploying.

8. Occasionally, for no reason whatsoever, your car would lock you out and refuse to let you in until you simultaneously lifted the door handle, turned the key and grabbed hold of the radio antenna.

9. Every time a new car was introduced car buyers would have to learn how to drive all over again because none of the controls would operate in the same manner as the old car.

10. You'd have to press the "Start" button to turn the engine off.

I got it from "Roger and Me" a documentry by the well know icon of truth Michael Moore.

I got it from "Roger and Me" a documentry by the well know icon of truth Michael Moore.

Safe mode on your car is called "Closed Loop Mode", when you have a CEL on, your car will go from Open Loop, to Closed Loop, and the ECU will run on its lower performance fuel map to lower the risk of damaging other components.

Interesting - you have me very curious now. Do you think you could expound upon your explanation? Is this only with the CEL or with other possible error lights? What kind of "lower performance" - what does that entail?

Please enlighten me!

Hi,

Actually, this is not true. You have Open Loop and Closed Loop confused.

Open Loop mode simply means that the ECU does not monitor the O² and other sensors to adjust fuel delivery – it is not receiving or using ‘feedback’ from the engine sensors, therefore, it's really not a Loop at all, but that's what they call it nonetheless.

Closed Loop means the ECU (DME in Porsche parlance) monitors the O² and other sensor voltages and adjusts the fuel injector pulse width and Spark Timing accordingly to meet the sensed conditions using a number of target Maps designed for performance, load, etc.

In Open Loop mode, the 0² sensor is not controlling the mixture. Typically this occurs during warmup before the sensor is up to operating temperature, and also at WOT. In Open Loop the mixture is controlled by the ECU applying default maps. This is what happens in SAFE MODE (this is a misnomer, it is more accurately a Default Mode). The sensors input is outside of the pre-programmed parameters and the DME doesn't know what to do so it goes to it's default mode. This is more to maintain low emissions than any protective function, this usually results in less performance, but only to keep emissions as low as possible.

In Closed Loop the DME is reading the 0² sensors along with other sensors and using their signals to adjust Mixture and Spark. It's referred to as Closed Loop because it's a "feedback" system, where the ECU constantly reads the sensors, makes adjustments, checks the results, etc. hundreds or thousands of times a second.

If you are having issues which cause the car to stay in Open Loop operation, this probably does not have anything to do with starting, look for other coincidental causes here. Open Loop s/b one of the most start-friendly Fuel/Spark Maps. Hope this helps...

Happy Motoring!... Jim'99

I bet your right, but im too tired to read/understand your entire post...