Help with 1.8T 156 sportwagon - accumulated electrical gremlins
I've had my 156 1.8T sportwagon for 4.5 years (one of the first in the UK). It's had it's fair share of mechanical problems (threw its timing belt, warped brake disks and binding calipers etc), but until recently I thought I'd avoided the curse of italian electrics. However, I now have the following:
1. Intermittent failure of most dash board instrumentation (speedo/odometer), which occurs at the same time as an overall failure of instrumentation panel lighting. When this problem occurs (increasingly common over the last two weeks), the backlight for the main instruments fails to come on. The speedo also stays stuck at zero and the odometer and trip displays are blank. There's also no light in the oil and fuel meter binnacles. The rev counter does however register the correct value.
I haven't yet had the problem occur whilst driving: the car either starts okay and remains fine or it starts without instrumentation and then either remains out of action for the journey or spontaneously remedies itself at some (seemingly random) period afterward.
When it comes back to life, the lights come on, the speedo starts registering the correct speed and the odometer appears to "reset" (shows "all the 8s") before reverting to the correct accumulated distance (about 87000miles now).
I guess the ECU is involved in this problem, rather than it just being a loose connection for the instrumentation backlight (due to the way that the odometer display "resets" itself when it returns to life).
2. Remote alarm and central locking seem to have gone out of sync. Can only use key to open doors (at least immobiliser hasn't kicked in).
3. Airbag warning light permanently on.
It's about time to trade her in, but I at least want to fix "1" (instrumentation) as cheaply as possible before I take her to my nearest car supermarket for a swap with a newer model.. Any ideas.?