Cadillac Repair: 1991 el dorado, exchange unit, climate control

Question
I've done lots of work to this car -- getting new message that says "service soon" then switches to "to owner's manual".  During both messages this remains "-3".  These appear in the Driver's Infomation screen.  Any idea what it means?
Repair work: most recently the A/C.  Also water pump, very recent tune up, Distributor, brakes, etc, so hopefully it isn't any of these things.
Thanks for your help.
W

Answer
Hi W,

   Electronics are kind of weird in what they will do when they are starting to go bad. I had a 13" TV that lost its sound and then it displayed a 5 digit code in the middle of the screen while a #9 was in each corner.

   As for your particular problem I haven't heard of that happening or remember seeing any bulletins. What I would suggest is going into diagnostics by pushing off and warmer on the climate control for 5 seconds or until it goes into diagnostics. The key will need to be on or the engine running. See if there are any current codes that show up as EE_ _ or FF_ _ and that could lead to the fix. Next thing I would do is to disconnect the battery for 30 minuets and after you hook it back up see if the messages return. You will need to relearn the tps and idle after the battery is hooked up or you might have a 30mph idle. My last thought is that the display panel will need to be replaced. I would monitor the messages and see how often they return and if the panel stops working correctly. If it does then I would be tempted to replace the display panel with a used one from the junk yard. Or if you have a really nice car then it might be worth it to go to the Caddy dealer and get an exchange unit or have them sent yours out to be tested and/or repaired.

      Hopefully I have been of some help. Bill