Re: replace crank and cam sensors together?
Crank and cam sensor "should" throw a code.
Relay Control Module will not throw a code and can stop your car in its tracks as the failing solder joints deal with the fuel pump.
I doubt VERY seriously that just a relay was changed. It's one of those replace the whole item and call it fixed (unless you are part of this forum!).
Yes the replacement RCM could go "bad" again after a year. The solder joints are just plain poor in that lower part of the board. On some of the RCMs I have repaired the poor solder joints are on other areas also.
NOTICE: You NEED to look at the joints with magnification. With the naked eye things may look just fine.