Hmmm, that could be a reason, but:
All Vanagons use the same control unit, no matter if 2WD or syncro.
On the other hand, a unit that works with half the impulses will also
work in a syncro with standard impulses. So 4WD wouldn´t matter

I used the 443 unit on a 2WD, but I can´t remember if it started working
at higher speeds only.

Regards
Raimund

mark drillock schrieb:
> I wonder if the 2wd Vanagon uses a different control unit due to the
> speedo cable driven speed sensor only spinning at half the speed that
> it does in the VW cars. Syncro speed sensors turn at about the same
> speed as the cars. What type of Vanagon did you have?
>
> Mark
>
>
> Raimund Feussner wrote:
>> The Vanagon also shares the vacuum pump, the throttle control element,
>> the brake/clutch valves.
>> You can also use the control unit itself, although most cars use the
>> 443... part number from the audi 100/5000 (even Passats etc).
>> The vanagon uses 251 number, but the audi part definitely works in the
>> vanagon (similar pin assignment). I used it for two years in my Vanagon.
>> Maybe the vanagon part has a different software setup which will work
>> smoother in the Vanagon, but however the 443 unit will work...
>>
>> Regards
>> Raimund
>> BTW: most of these parts can be found in any VW/Audi up the mid/late 90s
>>
>>
>>
>>
>> miguel pacheco schrieb:
>>> Wondering if any of the Rabbits shared cruise control parts with the
>>> Vanagon.....as in the switch on the blinker stalk that I've been
>>> trying to hunt down?
>>>
>>> --
>>> Miguel
>>>
>>