You need to reset the OLM manually.Do you have an owners manual?
Service Engine Soon
You need to pull your codes. Go to either the Eldorado/Seville, or FWD Deville/Fleetwood forum, and read the "sticky" thread on how to pull codes. List any codes you may have, AND THEIR DEFINITIONS, here (there's a link within the sticky to code definitions).
I am reasonably sure the sound system in your 90 is the same as my 91. Mine is Bose and is labeled Symphony on the faceplate as well. In this system each Bose speaker has a dedicated amplifier controlled by a "receiver'' located behind the glove box. The receiver is controlled by the buttons on the DIC over a data bus. Over the years the capacitors in the amplifiers have leaked causing the amplifiers to fail. In some instances the amplifiers can be brought back to life by replacing the capacitors.
Traction control can be turned Off by disconnecting the electrical wire that loops through the spare tire. Since the spare is not the correct size, traction control needed to be Off when in use and to remove the spare you needed to disconnect the wire.
ABS disabled indicates the Anti-Lock brake system is probably inoperative. This vehicle uses a Bosch III ABS system and on 90-92 the Traction Control and ABS are integrated. This system uses a very high pressure hydraulic system MAKE SURE you understand how it works before taking anything apart. Check this link for more info: www.allantesource.com/techtips.htm.
Thanks for the replies fellas. I'm going to get to work on some of the things I've read here.
@D Yaros, I have a Service Manual for an '89 but it doesn't seem to address anything on my '90 model except for resetting the Oil Change light.
Also, I have a new problem. The back of the convertible top doesn't seem to want to meet the motorized latch. I know the latch moves up and down on its own but it no longer seems to work by pressing the rocker switch behind the drivers seat. There's about a one inch gap where the back of the convertible top should meet the latch.