MFA nach Spritspar-Tuning | Posts 16+

"Yes, my warning light usually comes on when I accelerate. It has never gone off again, no matter how slowly I drive afterwards. Also, the numerical range displayed doesn't increase again like it sometimes does."

HI,

Quote:

Yes, my warning light usually comes on when I accelerate. It has never gone off again, no matter how slowly I drive afterwards.

It doesn't seem to be intended in the software, unless a SIGNIFICANT increase in the measured resistance in the tank sensor is detected between two starts.

Reason:

My AI system has a problem with its power supply (I hope to finally fix it this summer), which causes it to occasionally reset. This is equivalent to a blown fuse or a disconnected battery, and it not only results in the amusing up-and-down movement of all the gauges, but it also causes the fuel level to be read directly from the sensor (normally, the car would otherwise account for this). This has happened to me twice while I was driving in a curve (once on the ADAC track in the endless curve...), so the fuel was not exactly horizontal in the tank, but pushed to the side. The result was that the display remained just above zero (half a tank!), and the warning light came on. Over the next 20-50 kilometers, the fuel level slowly increased again, until it reached its normal level. Despite the tank being half full and the range being over 400 kilometers, the warning light did not go out. It could only be reset by pulling the fuse or refueling (or by the next occurrence of the power supply issue).

The relevant value for detecting overnight charging appears to be the sudden change in the measured resistance value, rather than the smoothed and filtered slow changes that occur during driving, or the slow adjustment that happens in the case of a start with an incorrect sensor value.

Best regards,

Jan.