2000 w220 no communication (can bus)

2000 mercedes w220 can bus issue

Hey guys listen I got this 2000 mercedes w220 in limp mode 2nd after 1min of normal driving to verify my neighbors complaint Yes its stuck in limp mode along with fuel limeter so I tried to pull codes and there is a communication error! my scanner is a snap on solus pro with all the personality keys prompted by the scanner, and still no communication with any modules on the menu, so I tried global obd2 and a very slowly it comes back with po715 its has a 104k also on thee odometer there's 3 malfunctions abs/bas, electronic stability control, and coolant level,
Knowing I'm already changing the conductor plate and the brakes light switch, the tcm connector is dry. but I also knew I would need to clear codes after replacing those two items, ok so with out being able to access any of the vehicles modules directly ... I tried to think logically I know I'm having a communication issue with this vehicle, I noticed that some genius installed a double din Kenwood dvd player and simply unpluged all the radio connections and the fiber optic connection question 1) is this the likely cause of the issue with the no communication error? 2)if so is the only solution to replace with a compatible command or is the problem likely elsewhere. 3)will the solus pro be able connect to affected modules. Once Comm error is rectified
Thxs for reading! all replies appreciated
KARMIE,