One problem related to automatic transmission control module has been reported for the 2000 Saturn LS. The most recently reported issues are listed below.
2000 Saturn Ls, 6 cylinder, had slippage of the transmission followed by the service light. By the time I reached the dealer the car was bucking and felt like I was repeatedly being hit from behind. The mechanic told me it was the sensor module and when it broke the pressure was full open and that's what caused that problem. Subsequently the light came on again, the transmission slipped and the module was replaced again. It then happened a 3rd time and the module was replaced again. When driving it home after repair, I noticed that the trans was slipping a little. Took it back into the shop, they say they can't rip down the trans unless the light comes on and it gives codes again. I only have 11,000 miles on the warranty. I believe there is another problem with the transmission.