the last truck i repaired with code P0237 and P0193 turned out being the rail pressure sensor. if you can monitor rail pressure, check to see if there is a spike in pressure when the chatter starts. Also found a tech tip on chrysler's database for P2509 and found something to try first, might work, unplug the 6 pin connector for the cooling fan and see if the trouble is still, something about intermittently shorting internally. Haven't come across this, but makes sense. Can cause multiple codes. Good luck.
