DIS parameter display haywire

[Geraldy212]

On my 2006 TDI 140, I am pleased to be able to display the fuel used (kilometers/litre) and of course the averages. However on a recent long trip to the UK from France, the displayed figures were all haywire. The fuel-used display on computer 1, instead of giving a slowly changing number, kept on changing in a very erratic manner. Flicking from 18 k/l to 25, to 85, and then back to something like 22 in succession. It is supposed to take a reading every 30 meters. Previously it has worked very well. I am also suspicious of the numbers shown for average fuel used, which now seems to be far too low. Other displayed numbers such as trip times, fuel range etc, are working OK
Has any member suffered this instability, and does anyone know what would bring this facility back to normal? Does this calculation need an input from a fuel-flow sensor, or is it just a computer calculation? The car has recently been serviced, so I assume it was checked with VAGcom for errors. Everything else on the car is working just fine, just these displayed numbers on the computer (1 and 2) are erratic. Would disconnecting the battery help to reset the onboard computer?
Would very much appreciate any comments/suggestions from members.

 

[audi58]

you sure you're not getting instant fuel consumption and average fuel consumption mixed up??

 

[Geraldy212]

No, I don't think so. Previously, the kilometers/litre would be a fairly steady reading, which would increase when I was gentle with the throttle, and improved a lot while running on the motorway at constant speed. All very logical. Now. it keeps on changing, and does not settle down at all. The average fuel consumption figure has a little 'star' in front of it, and stays steady, but now seems too low.

 

[audi58]

Okay, I think you've been getting mixed up. Possibly, not sure though.

Computer 1 shows journey information and computer 2 shows info about the car until you reset it.

To get what you're wanting, go to computer 1 and then scroll along to average km/l (the one with a circle and a line through it as the symbol.)

 

[Geraldy212]

No, not mixed up. Have just reset the average KM/L displays on both computer 1 and 2. Taken the car for a short trip, and the normal KM/L value (not the average) is still hopping about all over the place. It looks like it is indeed trying to update the measurement every 30 meters. This fault has been seen before last year, but seemed to fix itself after the ignition had been turned off and then on again.
Does any member know if these measurements are done within the instrument cluster itself, or are the displayed values calculated elsewhere in some other computer? Perhaps all I have is a poor connection somewhere and a key signal is not getting through. Is this the kind of fault that would show up on VAGcom? Any help appreciated.

 

[Geraldy212]

Bump..... Does anyone have a Vagcom in the south of France?