Vehicle speed sensor + Throttle potentiometer fault?

[JamesBaby]

Hi, I'm getting a fault code occasionally on the above mentioned 2 items. Is the "Vehicle speed sensor" the same thing as a Crankshaft sensor?,

also the Throttle valve potentiometer is coming up on Vag com too. This I understand is bolted to the Throttle body. Is this a servicable part, i.e can i open it and clean it etc, or replace that specific part of the throttle body?

My engine is the 97 8v AGG

[bored_Welsh_lad]

vehicle speed sensor is different to crank position sensor.. i believe the speed sensor is exactly that and provides the speedo signal from the gearbox...

throttle valve is a small electrical item which is on the throttle body, it has the butterfly spline running through it and tells the ecu how wide the throttle is open...

you can reset this.. im not 100% sure how though...

[JamesBaby]

Thanks for the response.

The problem I have with the TVP is that once I have driven for a while and the engines hot, when I lift off the throttle or press the clutch, the engine cuts out. It starts up again no problem though. Upon checking with Vag Com it says that the Throttle Valve Actuator has an intermittent fault.

The TB has been cleaned out etc, but it still does it. Hence my question as to whether some attention could be given to the TVP on the side of the throttle body. I was thinking I might spray it with some electrical cleaner spray?

Any thoughts?

[Christo77]

Sorry to bump this one up again..but,
As a matter of course I thought I'd look into replacing the Crankshaft sensor and the Throttle position sensor on my 8v..so off to the VW dealership i goes.. and they tell me £170.00 for the Crank sensor and £300 + for the Throttle sensor!  the man say's you get the whole Throttle body, the sensor isn't a seperate item!
Can any of you guys confirm this and the prices? seems a bit ridiculous to me..

Thanks

[JamesBaby]

yep, sounds about right. I had the same issue but don't buy anything until you have done what i did. I solved it by doing this:

1. Clear the fault codes with Vag Com or similar, then disconnect battery
2. Remove cable connector that goes into TB, clean with electrical contact cleaner. Allow to dry.
3. Relocate the cable loom that goes to TB and injectors away from the hot manifold. Inspect for damage. Move the loom towards the injectors.
3. Clean out TB with carb cleaner. Also spray into TB from right hand side where the hard vacuum pipe attaches.
4. Reconnect battery, and insert ignition key and turn to position 2 (i.e just before starting). Leave for 30 minutes. (Watch no one steals car.)
5. Restart the vehicle.

Completely eradicated all stalling problems and fault codes for me.

[Christo77]

Ah..that's interesting, appreciate the write up there..
Does look like i'll need this Vagcom program though, i take it you get it connected to the vehicle via laptop means?

Cheers

[JamesBaby]

Most definitely, for the sake of a few quid spend money where needed, rather than shooting blind and hoping it works.

http://cgi.ebay.co.uk/USB-VAG-COM-VAG-COM-409-1-OBD-2-II-CABLE-LEAD-AUDI-VW_W0QQitemZ230383853575QQcmdZViewItemQQptZUK_Diagnostic_Tools_Equipment?hash=item35a3f2a007&_trksid=p3286.c0.m14#ht_2782wt_850

Easy enough to use.