Vehicle speed signal in Typ 89

[Huw Powell]

> So as I can see there are two possibilities:
>
> 1. a solder joint somewhere in the instrument cluster is bad; 2. the
> vehicle speed sensor is bad.
>
> Option 1 is no big deal, it does not affect the car's operation.
> However, option 2 may mean that the ECU is getting wrong information.
> So the big question here is:  does the speed sensor supply
> information to the ECU?  Put differently, are those high fuel
> consumption figures I get while the needle is oscillating true or
> false?

no.  trip computer information is to be taken with a grain of salt.  the
trip computer gets info from a few things that matter, but does not
affect them.  your speedo wire could be cut and dead and your engine
will run just the same.

> BTW, I took the speed sensor out of the transmission housing, cleaned
> the electrical contacts (2-pin) and put it back.  No difference.
> Would anyone know how to test the sensor for output?

I don't, but if anyone tells you privately, please let us all know.

--
Huw Powell

http://www.humanspeakers.com/audi

http://www.humanthoughts.org/