Topic: Possible bug?

I have my S5 screen gauges set to EGT, supercharger revs and boost. Yesterday whilst driving I noticed that the supercharger revs needle was at zero, and even with the clutch open it is always at least about 200rpm which is noticeable. I cannot be 100% sure that the other two needles weren't also at zero but I think I would have noticed if they were.

So I changed to the measurements list screen and indeed the supercharger revs were 0. But I also noticed that the battery voltage was about 11.7V, which for my car under those circumstances it would normally show over 14V. Again I wish I had been paying attention to the other values but I didn't, however I feel fairly sure that I would have noticed if they weren't right.

Even though the car itself wasn't warning me of trouble I stopped to check the drive belts. Both were OK. So I got back in and started the car and it was back to normal with expected supercharger revs and battery voltage. I then continued on several journeys and everything was fine.

I had done an aggressive VCDS autoscan the day before and there were no faults. I have just done another one and there are still no faults. So the only reason I have to suspect that anything is wrong is due to those measurements shown on FIS-Control MMI.

Re: Possible bug?

Thats hard to tell. Can you send me your configuration file?

But I am pretty confident, that the FIS-Control shows the data that it receives correctly.
If you see such strange readings again, you could try to exit the FIS-Control, so that you see the normal MMI on your display. And then enter the FIS-Control views again. This way, the FIS-Control will reconnect to the engine control unit.
If you still have wrong readings, you could exit the FIS-Control again and connect VCDS to see if it shows the same values.

Re: Possible bug?

Thanks Stefan, I will certainly try that if it happens again. I have e-mailed the file.
I am interested why the voltage should have been shown as about 11.7V. Do you know if maybe that is actually the minimum value for that register?

Re: Possible bug?

The minimal battery voltage that the FIS-Control can show is 0.00 volts.

In your config file, I can see that the compressor speed and the battery voltage are the last two values that are on the list. This is at least the place where I expect a bug to happen. This is because all the parameters are hold in an array in the memory of the FIS-Control. If one item is longer than expected for whatever reason, it might overwrite the memory of the following values. So this could lead to corrupt values of the parameters at the end of the list.

I still don't think that there is such a bug in the FIS-Control. but please keep an eye on the readings. If anything is suspicious, try to find out, if it is really the FIS-Control that is doing something wrong.

Re: Possible bug?

Stefan, I just loaded my config file into and it shows measurement values for #8 and #9, but without label or unit. Since with my ECU only 8 measurements can be used, could this be a problem? Should I try to create a new file where #8 and #9 are totally blank?

Re: Possible bug?

There is no need to change the labels. The FIS-Control will ignore the last two entries anyway, because you set the "used formulas" to 8.

7 (edited by Dippy 2019-10-02 14:44:32)

Re: Possible bug?

Stefan, this happened again last night. I have much more information in case it helps:
1) I noticed it after pulling out from a junction where the car had activated stop/start
2) All 8 values were frozen, and to values that matched the engine having stopped. So for example the battery voltage was below 12V and the supercharger revs were 0prm. But I had positive readings for EGT and oil temp which were realistic for the engine status.
3) The 3 gauges were also frozen, matching their 3 values.
4) I was able to use the roller to switch between the 2 FIS control MMI screens and the MMI screen (as per your suggestion in#2 above, so this did not fix the problem).
5) I held down the MODE button until the setting screen appeared (I did not know this screen existed). I could use the roller to change the line selected, and the mode button ticked and unticked the "automatic start" checkbox.
6) When I rolled down to select the "Engine information" line (or similar title) the screen went black apart from the line at the bottom. Now the roller and mode button did not change anything.
7) The line at the bottom showed temperature, time (frozen to the time of the event) and the bluetooth icon (the notification icon had gone).
8) At the end of my journey I switched off the power and restarted - and it was all back to normal.

I have one more comment, but I don't know if it is related. For a while I have very occasionally noticed that the screen has changed from the 3 gauges to the MMI screen (SatNav map) without my doing anything. I thought it might have happened after stop/start, so I checked that and it wouldn't change on its own when I was watching it. It is rare and I haven't seen it happen, I just occasionally see that it had changed to the map so I need to put it back the the gauges.

Re: Possible bug?


thanks for the very detailed description.

My assumption is, that the engine might have dropped the OBD connection during start/stop.
The FIS-Control normally should detect that and should try to reconnect. Maybe this is not working properly.

From your oberservation it is clear, that the FIS-Control didn't hang, as it responded to the steering wheel buttons.

I will investigate.

About your second obersavtion with the FIS-Control changing back to the satnav map... no idea why this happens. Do you have the "Show and hide the FIS-Control with the roller of the multifunction steering wheel" option enabled?


Re: Possible bug?

Yes I do. That's what makes the roller switch between MMI, gauges and the list of (in my case 8) measurements?

Re: Possible bug?

Yes, that is right. Maybe the roller generates an unintentional click from time to time.
If you want, you can disable the "Roller" feature and check if the unwanted switch is seen again.