blackfnTTruck

I show 4 ohms from terminal 2 to 3 and an open between terminals 4 and 1. I assume this is like a mini transformer for the spark, like an ignition coil. I assume 1 to 4 should measure something. Does any know which terminals actually go down to the spark plug?

Audiboy

Therefore, the power pin connector will go directly to coil power primary. The ground pin connector should connect to an internal MOSFET swith. One pin from the connector will then connect to the ECU to power the MOSFET gate. Then the last pin on the connector should connect to ground, but only to connect to the MOSFET switch, and not the coil.

If you need to check resistance of the primary coil (through series MOSFET), you may need to connect the gate pin to power (Try a 3V or so battery)

To check the secondary, high voltage winding, you can probably check the output after you pull that connector out, and then one of the wires on the connector. It will probably be the ground one. You should be looking at low ohm values, like a transformer as you stated.

blackfnTTruck

coil pack, that's why 1 and 4 are open, because I'm looking across the drain and source of the FET. Although most FETs have a suppression diode across drain and source so you would think I would read that in one direction. Thanks for your input. If nothing else I am always learning something new.