I'm looking for a bit of guidance in troubleshooting this. The car is a 2005 612 with 25k miles. Here we go: This started just over a week ago when, after driving the car quite a distance on a Friday, found the battery completely drained 2 days later. In summer I drive enough to not have to put it on a battery tender, but the battery being drained in 2 days is the main reason why I have a theory as to what this problem might be. Still, didn't drive the car until a week later (car was left on the battery tender just in case). Car drove fine to work (a 30 mile trip) and then, on the way back, things started going downhill. On a somewhat bumpy highway, I got the suspension control system failure light. Car didn't feel any different, and I was on my way home already. A few moments later (maybe a minute or two), the engine control system failure warning joined the party. I pulled over and restarted the car just to see if this was a matter of resetting. It wasn't. What I did notice is that the car hesitated to start moving. I'd give it gas and it wouldn't raise revs much. Then it would hook up and chirp the tires. Once the car was moving, there was no bad behavior at all. Once home, I started with the simple stuff: Checked the battery. It was 6 years old. Figured it's time to change it anyways. Even after resetting the ECU (as per the owner's manual), the suspension control system light would come on soon after starting the car with the engine control system failure being added a few moments later. It's worth noting that after resetting the ECU and starting the car back up, the car would start moving just fine until the suspension control system warning would come on. The behavior (having trouble starting to move) applies in 1st and reverse as well as in manual and automatic modes. My current hypothesis is that I have a bad relay somewhere that drained the battery quickly and is causing all this. I'm not overly familiar in where to start looking, so any help would be appreciated. I'd like to see if I can tackle this on my own first (especially if it's as simple as a relay or fuse) before taking the car to a shop. Thanks for the help!