Dodge Repair: 96 caravan 2.4 coil pack, jumper wire, caravan 2

Question
my son has a 96 caravan with 2.4 engine. the coil pack is only firing on 1 side. he put a jumper wire from the lead to the other side of the pack and can get fire thus eliminating a bad coil pack. what exactly tells the pcm when to fire? and what are some of the possibilitys it could be

Answer
IGNITION COIL PACK (2.4L) CAV CIRCUIT FUNCTION
1 K17 18DB/TN NO. 2 IGNITION COIL DRIVER
2 A142 16DG/OR ASD RELAY OUTPUT
3 K19 18GY NO. 1 IGNITION COIL DRIVER


pin 1 and 3 are ground signals from the pcm   pin 2 is 12v from asd.

U are not looking for a sensor to tell when to fire the coil  it is already working because u get fire on 2 of them already.  U will be looking for a bad pcm or wire from the coil pack to the pcm.