PhilM

Hiya guys, just wondering if you can help shed any light on this problem.

Right, when we drive the VW Sharan (2.8 VR6 engine), and we reach about 3500rpm, suddenly the speedo will just rise rapidly to 140odd mph, just takes off, and the dash lights all go funny, ie, we get the low fuel warning light on when the gauge shows full.....ABS light etc.

Sometimes both Tacho and Speedo will flick all the way to max, then back down to min really quick aswell...asif its doing a reset.

We connected my OBD2 scanner to it and we get a few fault codes, Camshaft Pos Sensor Short to B+, and also Vehicle Speed Sensor eath to ground Intermittent.

Just wondering if you had any ideas? We have a new dash unit, but havent tried that yet.

Sounds like an ECU problem to me, as when it does go funny (~3500rpmish) we occasionally lose the OBD2 link and it has to reconnect.

Any ideas lads? Much appreacited

Rick

sounds like a bad earth to me

PhilM

Where Rick

Doug

V.S.S. will cause this fault and you also have a fault code for it so it sounds a safe bet to start there and prob the cheapest and quickest route

markk

iTrader: (2)

earths are a real problem on vw's , also the dash panel insert itself has a tendancy to give up

PhilM

Thanks guys....

VSS Sensor i have my reservations about, if I clear the fault codes, and we provoke the faulty again (high revving), then the dash will light up like an xmas tree, the speedo will shoot off round, but the fault code doesnt reappear!.

Strannge.....we'll replace the dash clokcs and check the earths behind the dahs I think.....ya cant see fook all in that engine bay though! Its a nightmate!

markk

iTrader: (2)

the V6 is a beast to work on , check alt output voltage as well , if i think of anything else , hmm what year is it ?

PhilM

I forget, its a mates mrs' car, S Plate IIRC!

markk

iTrader: (2)

hmmmm the old shape then , try what ive said , if not ill have look in the manual/tech bulletins at work

DazC

iTrader: (1)

For Mark!!

Glad to be of no assistance what so ever!

Sounds like it could have an earthing problem. Check the ECU main earth as well.

I haven't really done much on VWs so can't really assist much unfortunately..

markk

iTrader: (2)

your better off m8 , there a fookin nightmare for wiring faults , and the diagrams are fookin shite

DazC

iTrader: (1)

I'll stick to my trucks!