P0715 is a can bus issue on the Crossfire. Read this post Number 13 in the thread P0715 and P0705
Click the links and be sure to read them.When you replaced the conductor plate did it come complete with new solenoids and sensors, or just the plate? Could be you reinstalled a bad sensor.
Have you scanned the wheel speed sensors or replaced any of them?

PS After going back and reading your other thread/post it may be best to find a good independent shop that specializes in European/Mercedes and have them scan the car and then clear the code. Be sure they put in writing the exact codes they found and use the correct Numbers not some description like " It's the speed sensor" Get the numbers. Good Luck!