Intermittent Speedo/Trip Computer

[GrantGam]

Hi guys,

In the process of putting the S2 up for sale and just trying to sort out the last niggle before I do.

Basically, my speedo and trip computer don't work. The needle moves but it's slow to respond and will often hover without actually following the car as it speeds up/slows down. Often the speed is arbitrary, sometimes it's close, sometimes the needle stays at around 0mph. When the car was last in the garage, I asked the mechanic to take a look at the connections at the diff, and he said all appeared sound there. I'm assuming that the G22 connector was what he checked and it was apparently fine.

My MPG remains static at 23.5 - I assume this was the value it last read before sticking...

All other gauges (including RPM) work properly, it's currently how I gauge my speed.

So I'm seeking some advice on where to look next? Under the dash, under the bonnet, any advice on where to look and what to look for guys? Would going in behind the instrument cluster be a good idea? Maybe a poorly seated plug or something?

Cheers
Grant

[Mikes2]

23.5 is the default reading. I'd be willing to bet your average speed is 0. If it's not getting the speed signal, that's what you usually see on the trip. If the gearbox sender is all in order and the wiring is good, you need to take the cluster apart. Possibly bad solder joints, track damage or dampness

[GrantGam]

23.5 is the default reading. I'd be willing to bet your average speed is 0. If it's not getting the speed signal, that's what you usually see on the trip. If the gearbox sender is all in order and the wiring is good, you need to take the cluster apart. Possibly bad solder joints, track damage or dampness

Thanks Mike! Yes, avg speed is 0 also.

Was having a read through this:

http://forums.quattroworld.com/s4s6/msgs/168463.phtml

Just over half way down the page, where the guy has split the red connector block - would I find this under either the driver or passenger's kick panel? As my speedo is moving, and not totally static, I must be getting some sort of signal - just a *****/intermittent one?

So either a poor connection at the differential
Poor connection at a T6c connector (if the S2 ABY is the same as whatever is shown in the link?)
Poor connection into the instrument gauge cluster

Is there anything to physically measure with a multimeter to prove the speed pick up/sender ring sound? The article does suggest rolling the car forward whilst holding a multimeter under the foot-well; which could be... interesting.

[Mikes2]

ABY is different from that I'm afraid. Here's the relevant wiring diagram for the ABY :
http://s2-audi.co.uk/workshop/schema..._aby/page8.png

[GrantGam]

So it's looking like:

-Red and yellow core from the sender on the gear box to an 8 pin connector block in the right of the engine bay. Any ideas where this one is?

-Red and yellow core from the 8 pin connector block in the right of the engine bay to a 10 pin black connector in aux relay carrier (drop down panel underneath the steering wheel).

-Brown and red from 10 pin black connector in aux relay carrier to instrument cluster?

[Mikes2]

I suspect on a rhd, the 8 pin connector is on the left side. There are 2 connectors where the battery would be

[GrantGam]

Thanks Mike, I'll get a dig around when I'm back home. Thanks for your help!