Auto Check System & Trip Computer - Tech Advice Needed

[Garth Gillespie]

Hello,

'92 100 CS Quattro

Couple weeks ago while driving the auto-check system let out a long tone
(same pitch as low gas) and the auto check display and the trip computer
went blank.  The beep went on until I turned off the car.  When I turned the
car on again there was no auto-check display, and no trip computer.
Everything else works fine.  I checked the fuses.

I have removed the IC, and now I am wondering which part has gone bad.  The
trip computer is easier to deal with as it comes off the back of the IC
pretty easily.

My tech question is, if the trip computer fails, will it cause the
auto-check system to not display?  Or does my problem lie with the
auto-check system board/display (buried deeper in the IC)?

I have found a used trip computer for under $90 but I am wondering if this
will fix my problem.

Any advice on this topic is welcome.

Thanks,
Garth Gillespie