1999 SE Avant - problems with dashboard lights

[Adam&Eve]

Hi. First time user of this forum. I have a 1999 Audi A6 Avant SE (petrol). Suddenly I've started having probems with the dashboard warning lights. On various occasions, the oil pressure light and the ABS lights comes on, and the RPM guage reads zero. This often comes on after about 10 mins from a cold start. Sometimes, it may go off after a while again, but I usually feel a click around the pedals area. Also, when I lock the car, the lights on the right hand side stay on. I then play with the indicator lights and the hazard lights and hope that I am able to "unstick" these lights when locking the car.

I've taken my car to the local Audi dealership but they have been of no help. They suggest replacing the ECU in whole because they think water may have gotten into the unit, but don't provide any analysis of how. They also want to charge me £1200 to do this.

Given the warning lights issue comes on and off, I suspect that the ECU is not totally faulty.

Does anyone have any advice please? Thanking you in advance. :o

By the way, someone had suggested that I clear out the blocked drain tube under the battery, which I subsequently did (this past weekend) but the problem seems to persist.

[auiron]

Hi, may be a faulty Brake Light Switch on brake pedal.

[mastertech]

common fault on A6 is a water leak through the pollen filter dueto seal damaged on housing or lower screen trim not fitted correctly. water gets into L/H foot well where central locking/alarm ecu is fitted below carpet causing problems with indicator staying on and/or locking faults.
The rev counter/oil/abs lights sounds like a dash insert fault

[Adam&Eve]

Thank you. How do I fix this? With respect to the water in the L/H footwell, is it just a matter of drying it out? Also how do I fix the "dash insert fault"? Guidance would be welcomed.

[mastertech]

best way is to remove the carpet (seats/console out-3/4hrs) and dry out in warm room -the ECU is in a box under the passenger foot well-may dry out but usually requires renewing + wiring connectors may be damaged/corroded and require repair--repair wires available from dealer (best way of getting right repair wires is to get part number off plugs,dealer can then identify right parts. check water leak with carpet out--replace pollen housing /refit trim
If dash faulty ---replace---dealer only????