[Dan-danGT]

Hi all! I have a problem I hope someone might be able to help me with. I have a e90 330d well since my remap the obc on my dash is under reading. I.e I will work out the mpg on a tank to tank fill up it will average around 34 but on the dash 30 for example.

Well I read you can adjust it in the hidden menu, so i thought how hard can it be! Well I went into menu 20.01 which I believe is the overall value! So I went to 20.02 and so on but didn't realise it was adjusting the overall value. Anyway thought no more of it till today it's constantly reading 50mpg or there abouts when I cruising which it's never done. It's also has gone Upto 34-35mpg so far and there is no way on gods earth it's that good!

I don't suppose someone could explain how to set it up again or someone could check the hidden menu 20.01 and tell me there value but don't go any further then 20.01! Preferable someone with a pre lci auto!

[gaza01]

Press and hold the button on the end of the stalk to reset it...when u have the mpg display up

[Dan-danGT]

That's not quite my problem I can reset that its inside the hidden menu that I'm struggling with thanks for the help

[Dan-danGT]

I assume by all my replys that no one knows what I mean? I will just keep changing by trial and error!

[ronniemc]

I have never been into that menu, but I am guessing the correction factor has been changed, On my e39 OBC, the factory setting was 1000. Not sure if its the same for you

[ade146]

Dan just go all the way up and down to find max values and set it in the middle. I think it was about 700 mid val or something. I adjusted it from that to match the actual and havent touched it since. Set it back to 60 mpg before you sell

[M4rius]

you can duo via nsc expert too

[Alfamale]

Some of the less scrupulous tuners are known to tweak the mpg calculation values when remapping the car so the owner thinks they are now getting more mpg out of the car post remap.

[335DEE]

the value under menu 20.1 should be 1.00000 aka no correction

[Dan-danGT]

Mines something like 930 or 960. It's defiantly out but I like it as it fools my mind into thinking it's amazing lol

[marklemac]

I have the same problem and need to adjust my menu 20. My 335d is currently showing an average of 58.8, when it's actually 42.

When I get to menu 20, I'm not exactly sure what to do ?

[MrPogle]

Work out your error using the brim tank method then apply the error to the current menu setting. E.g. you are 10% optimistic on a menu reading of 950, set the item to 855.

[Hulla the Hulla]

My OBC under reads, for example today's fill up real MPG was 37.3mpg but OBC said 36.6mpg. Didn't know you could tweak it, glad I read this post now 👍

[apollo]

Taken from another site but it works fine for me

You should be able to get it within about 1mpg. 
The following is a procedure which might not be 100% perfect, so please review it as you try and give us any corrections. I put this together the last time we were discussing this on BMWLand, it applies to the E90/E91 and presumably E92. I think it also works for the E60/E61, and possibly the 1 series. 


1) Key fob in 

2) Press Start button without pressing clutch or brake if you have an auto box 

3) Electrics / ignition is on 

4) Press and hold trip reset button for about 10-12 seconds until OBC display changes showing something like YZ12345 where mileage normally displayed, at the top of the OBC display in small characters you will see 01.00 (Menu 01, sub-menu 00) 

5) Add up the 5 digits, so here we have 1+2+3+4+5 = 15 which is your UNLOCK code, remember it. 

6) Press and hold trip reset button for about 2 seconds until menu.sub-menu digits show 01.__, release button 

7) Press trip button repeatedly until 19.__ is showing and you see LOCK and below it 00, release and wait a second or so. 

8) Press trip reset button repeatedly until 00 counts up to your unlock code (e.g. 15), LOCK should change to UNLOCK. The extended service menus will remain unlocked even if you remove the key fob, until you come back to 19.00 to lock it again. 

9) Press trip reset button for 2 seconds until 19.__ displayed 

10) Press trip reset to menu 20.__ 

11) Below the digits 1000 should be displayed which is the current multiplication factor applied x 1000 (so it is really 1.000) 
==== Notes for the next step 
This figure can be adjusted between 700 and 1299 in others words a -30% to +29.9% adjustment. 
 We are applying this multiplication factor to a l/km fuel consumption number, which is an inverse scale to mpg. I tried a factor of 810 and got 96.4 mpg on a short drive through a town. 
For OBC reading an mpg figure 10% too high, I think the correction number needs to be 1100 to increase the underlying l/km figure which reduces the mpg result. 
My OBC was reading an mpg figure 2% too low, so I think I need correction number 998. 
The figure 1000 is adjusted as follows, the digits in the number are split 10 0 0 
==== 

12) Press the trip reset button, the right most digit counts up 0-9 and goes back to 0 until you press trip reset button again. Wait for the right value and press trip reset. 

13) Middle figure counts up 0-9, do the same again 

14) Left most digit(s) count up between 7 and 12, wait for the right value and press trip reset. 

Your done, unless you want to re-lock the extended menu by going back to menu 19.00. 
Key fob out, back in, start her up and drive

[MrPogle]

2% of 1000 is 20 not 2. So you would need 980 not 998.

[apollo]

Originally Posted by MrPogle

2% of 1000 is 20 not 2. So you would need 980 not 998.

Yes that is correct, formula is:
Correct fuel consumption in l/100km divided by OBC fuel consumption in l/100km x OBC parameter (normally 1000 or maybe different if calibration already attempted)

[Ao1]

Ask the CEO from VW

[BLKSAPPE92]

So the CEO from VW gave me bmw default is 1000 in hidden menu 20.

Then after some long bull sh*****g

Next Mister VW himself gave me the corrections.

actual mileage/indicated mpgX1000= corrected mpg