I wrote this as an answer to a question about L series computer problems on the other Saturn site and wanted to share it here.

The four cylinder ECM seems fairly reliable. The BCM appears to be the problem child on the L series cars. I have had 9 L series cars over the last ten years. Four were bought strictly for parts, two were rebuilt and sold. That leaves the four I still have. One of those nine has the first signs of BCM failure. It has the odometer failure that shows 694,*** and does not gain miles. It had this failure when purchased so true mileage is unknown on this car. Neither does the trip meter work, however the oil change minder seems to still work properly. The airbag module stores a VIN that matches the BCM so you have to change both to make everything work again. I have a matching airbag module and BCM to repair this car, I have not taken the time to install both and do the relearn. With my record with these cars I would not worry about impending doom of a BCM failure. I have had one ECM fail on the V6 car, I installed a used one from my parts supply and did the security reset.
Drive on my friend!