Looks like that sys error can come on for just about anything. My 94 had that light on since I bought it a year ago. Last week the trip monitor to right side of dash for all fuel switches, ilumination light would go on and off intermitenly. Friday I found the problem. a four prong plug was loose behind it.
Fix- remove 4 screws around speedomiter bezel and loosen.Reach up behind trip monitor and push plug back in. Next day I see sys error no longer there.
Fix- remove 4 screws around speedomiter bezel and loosen.Reach up behind trip monitor and push plug back in. Next day I see sys error no longer there.