This INJ Fuse 15Amp feeds all 4 coils and all 4 injectors on the two wires running downward on the diagram. The Igniters is built into each coil, thats why they are 4 wire. 1 wire is power, another is ground, then the trigger to the igniter inside the coil (IGT) and the 4th wire is a response signal to the ECM that the coil fired.
The igniter is just a power transistor that is turned on and off, instead of having it inside the ECM, this protects the ECM from being damaged if a coil shorts out or something else happens to the circuit.
I would go over each wire for the coils and make sure theres good power and ground to each coil and injector. Also check any bulk connectors for corrosion or pin fitment issues, that feedback wire being a shared wire between all the coils is one Id check for a short to ground with the key off, just make sure theres no continuity to ground. You might see a very dim pulse on the trigger wire with a test light, but it may be low 4 volt pulses.
Is that fuse is blown again.
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Saturday, December 6th, 2025 AT 9:35 PM