It's a '93, the first year of that model and I've replaced both S1, S2 soleniods AND trannies on those. They were known to have problems with those solenoids and we use to stock them too. The trannies still usually go past 140K miles w/o any fluid changes but probably alot longer with maintenance (fluid flushes on occasion, when dark, not red).
Given your low mileage, I'd get those solenoids replaced as that sounds most likely.