Bizarre electrical problem

[rgann]

My trusty 1995 A4 auto saloon is currently immobile The engine starts with no problem but depressing the brake pedal doesn't release the gear lever as it should. Other wierdness - the rev counter is now dead and the dashboard warning lights all come on - oil, temperature, handbrake and low fuel. So far as I can tell the other electrics - lights, wipers, indicators, even the Cobra alarm work as they should. Clearly this is an electrical fault but can anybody provide any pointers to where I should start looking? Could it be a relay? Or is the fault deep in the ECU?

TIA

Roger

[rgann]

The cause of my tale of woe has been revealed - water. The drain holes in the bonnet compartment that holds the battery became blocked. With the recent rainy weather that compartment filled with water and spilled over in to the passenger compartment footwells. And where is the gearbox management unit located - in the footwells. So it has got well and truly soaked. Apparently new ones are about £400 - any ideas of cheaper solutions? Can it dry out? Second-hand spares?

All suggestions gratefully received!

cheers

Roger

[RickT]

you can try a breakers... but if its shorted its goosed... you could remove it and let it dry out... or get a hairdryer on it on a low heat to dry it out,,

RicKT

[sh4h99]

my central locking ecu on my sharan went dead it was water that caused the problem i opened it sprayed wd40 all over the circuit board waited until next day put it back in and it worked but not everything only lights and alarm you could try that

[JohnnyBee]

Hi,Rog; the lads are right on this one; however as the TCU is all low-voltage stuff and doesn't actually switch any current as such, you'll probably find that if you open it up and leave it in a warm dry place for a few hours it will dry out OK and probably work properly.
Once you've got it reconnected and working, just take a little time to go round it with some RTV or bandage sealer to prevent a recurrence of the problem - an ounce of foresight is worth a ton of 'if only'!
JB.