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Old 04-02-2026, 02:20 PM   #11
bishopts

 
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Drives: 2017 2ss 6mt
Join Date: Mar 2024
Location: dallas
Posts: 1,485
Coil primary circuits are pretty simple circuits.
The coil is charged by applying power to one end and ground to the other. The wound wires create a magnetic field, break the circuit and the field collapses in the form of a high voltage discharge into the steel bar in the middle of the winding, which is where your spark plug wire attaches.
So the fusebox supplies the power in. Its going to be key hot and shared with the whole bank. Meaning if that fuse is bad then all 4 on that side will be dead.
Ground is suppled by the PCM. Its coil driver is an internal trigger mechanism. Simply connect to charge the coil and disconnect to fire the coil.
Since you dont have 4 dead coils it's not the fuse.
Since you don't have a dead vehicle its not the PCM ground.
It leaves you with power wire from the fusebox to the coil, trigger wire from the coil to the PCM, or the terminals at any of those connections to test. If all of them are good then your coil driver has failed and you need a PCM.

Very simple to test. Go to the point of connection at the pcm for the trigger wire. Key on engine off you will have battery voltage. That will test all of the wires and terminals in that circuit from the fuse.

If you don't have power there then look for power at the coil, both wires should have power. If one does and the other doesn't the coil is shorted or you have a broken connection in the connector.

Since you have replaced the connector. Double check your splices and make sure they have continuity. Dont twist wires together and tape them. Solder and heat shrink is easy and better.
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