Welcome back.
Pins 4 and 5 should not have power, but they should have continuity to ground. If that is what you meant, then you have lost ground to pin 4 and that is why a scanner will not connect.
Here is what needs done. Under the dash near the fuse box, locate the solid black wire from the DLC. That is the wire from pin 4. You will find it is spliced and taped to other grounds. Inspect it for condition, make sure the wire is not damaged, and make sure there is not a corrosion build up on the splice. If need be, make a new ground for it. Please make sure there is no power in the wire of any kind if you make a new ground. There should not be power. If there is, you have the wrong wire. You do not want to ground a power supply wire. Either it will blow a fuse (in the best case) or it could damage a component or start a fire.
I have attached a portion of the wiring schematic for you to see. Again, pin 4 is a solid black wire. Pin 5 will be a black wire with a white tracer. The schematic also indicates location.
Do this and let me know what you find or if you have other questions.
Take care,
Joe
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Thursday, October 11th, 2018 AT 5:19 PM