..how to do it?

or is it a con?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=9895&item=7915307444&rd=1

in brief display your speed on your cliamte control,and other things..rpm etc

Joel

Does this help (Speed is in KPH)

CLIMATRONIC SETTINGS

1. Press Fan Down, Temperature Colder, ECON at the same time.

2. Use the temperature control buttons to cycle through the various channels to Channel 16.

3. Press ECON to go back to normal. (It goes back automatically when you restart the car.)

The channels that I know the meaning of are:

1 Interior temperature (sensor)

3 Sunlight sensor

7 Coolant temperature sensor

9 Blower speed (adjustable)

10 Measured blower speed (sensor)

11 Defog valve (adj. 0-255)

12 Dashboard ventilation valve (adj. 0-255)

13 Recirculation valve (adj. 0-255)

14 Lower ventilation valve (adj. 0-255)

16 Speed (sensor)

OR

Contents of 1 system error # system error

2 actual value feeler virtually # actual VALUE sensor virtual

3 actual value of interior feelers console # actual VALUE internal sensor CONSOLE

4 actual value outside temperature feeler wasserkasten # actual VALUE outside temp sensor water reservoir

5 actual value outside temperature feeler bumper # actual VALUE outside temp sensor more bumper

6 actual value blowing out feeler floor space # actual VALUE bloweroutlet sensor footspace

7 actual value blowing out feeler Mannanstroemer # actual VALUE bloweroutlet sensor dashboard

8 display CHECKS #

9 actual digital value answering potentiometer temperature flap # actual digitally VALUE feedback potentiometer temp valve

10 debit digital value temperature flap # set digitally VALUE temp valve

11 actual digital value answering potentiometer A/C flap

12 debit digital value A/C flap

13 actual digital value answering potentiometer Fuss/Def. Flap

14 debit digital value Fuss/Def. Flap

15 actual digital value answering potentiometer ram air flap

16 debit digital value ram air flap

17 driving speed (km/h) 16

18 actual value of the blower voltage (volt) 19 desired value of the blower voltage (volt)

20 actual value of the compressor/on-board voltage (volt)

21 amount of of low-voltage events (not volatile)

22 switching status of the high pressure feeler

23 number of high pressure events (volatile)

24 number of high pressure events (not volatile)

25 A/D value kickdown switch

26 A/D value hot light

27 engine speed

28 compressor number of revolutions

29 coding

30 software-Version

31 software index of

32 potentiometer error counters temperature flap of

33 potentiometer error counters A/C flap of

34 potentiometer error counters Fuss/def. Flap of

35 potentiometer error counters ram air flap

36 temperature flap impact coldly

37 temperature flap impact warmly

38 A/C flap impact closed

39 A/C flap impact openly

40 Fuss/Def. Impact Def folds.

41 Fuss/Def. Impact foot

42 ram air flap impact on

43 ram air flap impact folds to

44 operating cycle counters

45 interior temperature counted (Nine) dig

46 outside temperature filtered

Switch your Climatronic to degrees fahrenheit (press auto and econ together) then enter the diagnostic mode and channel 16 becomes MPH.

And reads about 10% lower than the speedo on the dash.

The genuine reading is I believe somewhere in between the two

I agree, Dr. Z, it's a lot lower than the speedo... but I never said it was accurate

My GPS says almost exactly the same as you think... true speed is almost exactly between the two...