Non working fuel gauge and fake outside temp readings

[cav-mad-gav]

Hi all.

 

Having a strange problem with my 2008 2.0 tfsi octy.

 

Now and again the fuel gauge will just stop working, and every time it does the outside temp readout drops to stupid - 'C

Today it was -29 outside!!

 

The two always coincide so I don't think the temp sensor is faulty as how would this effect the fuel gauge?

 

The temp gradually rises in .5 increments through the journey but never gets to a correct reading.

 

Has anyone got any ideas off the top f their heads?

 

Thanks all

[cav-mad-gav]

Please anybody?

[cav-mad-gav]

Whats happened to this group? there used to be loads of people on here quick to answer?

 

Where has everyone gone?  :'(  :'(  :'(  :'(  :'(

[Breezy_Pete]

If it's any encouragement, I did have a look last night to see whether I could spot any commonality in the wiring of these two functions. I found unfortunately that I don't have mk2 Octy wiring diagrams.

Because the two functions use sensors in such different areas of the car, it seems most likely to me that the fault must be in the Instruments module from where the sensors are energised (I suspect) and their outputs are being processed and then displayed. I could imagine (for example)  that maybe both sensors are fed a constant voltage, generated by a single device on the PCB which has a cracked solder joint. Depending on temperature/humidity/vibration or whatever, sometimes that solder joint is 'good enough' other times it isn't.

 

Have you tried giving the clocks a tap when things start playing up?

[cav-mad-gav]

Hi Wino, 

 

Thanks for you reply and thank you for taking the time to look.

I also suspected that the two would be unrelated so your theory about the clock PCB seems pretty plausible.

I have tapped the clocks when it happened, started, stopped, hit the top of dash board etc....It really does seem completely random.

 

Oh well, i'll keep my eye on it and see if anyone else has experienced it and searches for this thread