I have a 2009 Dodge Charger 3.5 l V6. Recently the ABS and traction control lights came on but there weren't any noticable issues right away. Over the next couple days the car would go into "limp mode" and the speedo would drop to zero. I would pull over and shut it down and start it back up to temporarily fix the issue. I hooked up a code reader and was getting code P0502. I took it to my shop and they told me the speed sensors seemed okay. They recalibrated and sent me home. Car ran great for 2 days. Now today I had to shut the car off and restart 5 times for a 10 minute drive. ABS and traction control lights are on again. Now I'm getting code U1412. Google isn't helping me pinpoint the problem. Any suggestions?