Trip computer that talks rubbish

[demus]

Does anyone know if it is possible to calibrate the trip computer? its on my 2001 TDI SE.

The average will always read around 60mpg, when checked at the pumps it always around 50mpg.

The average speed seems to read correctly, the range will calculate with the mpg reading, and with a full tank will say 850 miles, but when the car gets down to around 1/4 tank, it will quickly go from 200 miles to 50 miles left as the car is obviously using fuel quicker than it says.

From a cold start it will quickly be reading 50+ mpg, just seems its always 10mpg out. Surely with the engineering in these cars it can work that out..
Just wondered if anyone knows why it reads like this or if it can be adjusted..

Cheers,

Mark..
2001 A4 TDi SE 130

 

[jwhat]

You can change it with VCDS afaik.

 

[Fabian1999]

Sounds like the problem I was having. I got a b7 Cab. I went on a motorway journey and the trip said i had 40 miles left in the tank. The guage was just passed the fist red line. Anyway parked up for 20 mins. Tried to start it up and it refused to start. called the rac. (the last thing I would have thought was wrong was that it was out of fuel) He topped up with gas and it started! even the guy said that the trip reading 40 miles is a big margin for error. So I think a calibration is also needed.

 

[Johnny Bravo]

I have the same problem. The computer is far too optimist when it comes to fuel consumption. It often shows a consumption with 1.5 liters less than real. IE: according to the computer I have an average of 7.5 liters/100km and when I refuel and do the calculations I get 9 liters/100 km.
I've noticed that the difference is higher when driving trough town. When I drive outside town the difference is smaller. I think this has something to do with the fact that my computer doesn't (or can't) show instant consumption when idling. And when I'm into town there is a lot of idle...

 

[sammi]

Ours does that too, is there anyway of fixing this easily??

 

[Johnny Bravo]

The only way I've read about is via vag-com. I don't know the procedure though.

 

[dansansome]

There is plenty of talk re MPG and mine was very optimisitc. I calculated the true MPG and took a percentage difference. It was about 10% optimistic! Why have a DIS that shows incorrent miles left and average consumption. I've changed this:-

17 - Instruments - Adaption-10 - Ch No. 3 - Origininal val 100 (this is a %) my new value is 110. Use TEST and see Average MPG drop in DIS!

i think you need to have a full version of vagcom for this adaptation

 

[3.0 TDI Paul]

I have a 2006 A4 (B7) 3.0 TDI with the DIS giving an average MPG 60% higher than actual. I've only had the car 2 months. My previous car was a 1998 A4 B5 2.5 TDI the DIS was spot on, so I'm a bit disappointed with the new one for that. My brother also has a 2002 A4 (B6) 2.5 TDI 180, his DIS is spot on too.

I've got the full version (ish, 704.1 fakely off ebay). I'm happy to try the adaptation, but is it a bodge? If possible I'd like to solve the cause of this. Any ideas?

There is one other thing with my car. When I bought it from the dealer (not Audi) I plugged it in and it had a lambda probe fault. I haggled with the dealer and bought the car. Replaced the lambda probe, the fault code came back but after clearing it again, it hasn't come back again since, however the car was and still is putting out a lot of black smoke. No other fault codes, checked air and fuel filter etc. I'm thinking the two are related but not entirely sure.

 

[Shades]

I went on a motorway journey and the trip said i had 40 miles left in the tank. The guage was just passed the fist red line. Anyway parked up for 20 mins. Tried to start it up and it refused to start. called the rac. (the last thing I would have thought was wrong was that it was out of fuel) He topped up with gas and it started! even the guy said that the trip reading 40 miles is a big margin for error. So I think a calibration is also needed.

Mine has started doing this, I've ran out of diesel twice even though the range said I had "plenty". It happened once when I was getting 4 new tyres, boy did the fitters rip the p**s out of me for that... especially when I took the missus car for some tyres the next day too ("You sure you got enough fuel in that?" etc, etc) Anyway, I digress... The difference I've noticed is that I used to drive around with bit of a led foot (nothing too naughty, just hard acceleration from junctions, lights etc). However recently I've started driving much more sedately and the range seems to be up and down more than a whores draw and even more rapidly depending if I'm on an incline or decline. It's completely doing my nut in.

I'm wondering if this has happened because of the difference in driving styles and the DIS (or whatever calculates the range) has gotten a little confused. Would disconnecting the battery for a few hours force the DIS back into learning mode? (I know this used to be advised for Jags that were having range problems). Anyone have an idea if this would work or is it purely a VAGCOM reset thing?

 

[demus]

Shades,

I did try leaving the battery off for a while to see if things would reset, but nothing really changed.

Surely they cant leave the factory this bad, we have a 2004 1.9TDi 130 at work and that reads spot on.

Mine seems to over react to very light throttle and coasting, far more than the one at work. On a gentle drive across town (about 1 mile), the car at work will barely hit 40mpg if very careful, mine will touch 60 sometimes!!