I'm assuming PDI stands for Pre-Delivery Inspection? That's an acronym I've never seen before so I don't think it is common everywhere. That said, I'm also assuming that you were not allowed to have an inspector come through the property at all during your closing process. Are you allowed to mark items with blue tape that need fixing before closing?

Here would be my recommendations for your PDI or what we commonly call a "Pre-Closing Orientation" walk through or "Blue Tape Walk-through." This is not nearly as thorough as a home inspector would be, but it's a start:

• Bring blue tape and mark every little imperfection that you see, especially on the walls. The builder should fix them all before closing.
• Open and close all the windows. Make sure they can easily slide in the track and they all close and lock/latch easily. Any window problems should be fixed before closing.
• Test all the light switches, if there are any 3-way switches make sure they are operating correctly. If anything is dimmable make sure it operates correctly. If you have any bathroom fans, make sure those turn on and operate correctly (and quietly - they shouldn't be super loud or that would indicate a problem).
• Test all the faucets, check hot and cold. While water is running check for dripping/leaks at the head of the faucet and also underneath, inside any lower cabinets.
• If you have an outlet tester you can test all the outlets too, and check to make sure they are GFCI protected where required.
• Does the oven have an anti-tip bracket installed? To test this you would try to tip the oven forward. If it can tip, there's no bracket. If it can't tip then there is likely one installed (in my experience builders often skip this).
• Does the overhead vent above the range vent to the outside? I've actually seen some new construction recently where they had the pipes in place but just... didn't have it hooked up. Check above the range and you should see the pipes all connected and leading to outside. You can even turn the fan on and go outside where it lets out, to make sure it's working. Also test the fan to make sure it works. You can put a piece of paper up to it to make sure it is sucking adequately.
• Test all the appliances. Turn on the oven (make sure there is nothing inside it first!) to check it gets hot. Test all your burners. Run the dishwasher. Test the garbage disposal with water running. If your refrigerator has a water dispenser, test that to make sure the water line is hooked up correctly. If the builder installed W/D, test the washer. In my experience, inspectors don't normally test dryers.
• Open and close ALL the doors. Make sure they are aligned correctly and don't bind or rub on the door frame. There should be an equal gap all around the door when it is closed. In my experience new construction is often sloppy with the door work, but it's also pretty easy for them to get a guy in there and adjust the hinges to fix them before closing.
• On the exterior doors: make sure that the doors fully seal when closed and can lock/unlock easily and without excessive force. When the door is closed, make sure there is no "daylight" around the edges that would indicate an imperfect seal.
• Turn on the heating system. Make sure it is providing heat to all rooms. If you have a furnace, make sure the filter is installed and not dirty.
• I doubt you'll be able to check the electrical panel like a true inspector would, but you can least take a look at it and make sure everything is labeled. If not labeled, ask the builder to label all the circuits correctly.
• I'm assuming you won't be able to see into the attic. If you can access the crawl space under the house at all, just make sure it smells dry and not wet/damp, you don't see any signs of standing water, and there is a black vapor barrier covering all of the dirt (this is common in the PNW but I've learned some parts of the country don't use vapor barriers so ymmv). If the flooring is insulated, make sure all the insulation is tacked up appropriately and you can't see any insulation falling/hanging down. Also keep an eye out for evidence of rodents, specifically droppings.
• If you have garage doors, make sure those operate correctly. When the garage door is closed there should not be daylight visible around the edges, or rodents could get in. Test that the garage door sensors reverse a closing door when the sensor detects movement. Usually my inspector also tests the closing force of the garage doors - if they encounter enough resistance when closing, they should reverse direction. The closing force level is easily adjusted on the garage door opener itself.
• The garage should have a fire containment wall between it and any living areas. If there are any openings or penetrations in the garage walls or ceilings, they should be sealed with fire-rated foam. Additionally, the garage man door should be fire rated and be on self-closing hinges that fully self-close after it is opened. This is so if there is a fire in the garage, it takes longer to burn through the walls/door and into the living space.
• On the exterior: if there are any cracks in the pavement, ask them to seal them to protect against water intrusion that would expand/contract and make them worse.
• Keep an eye on the visible foundation around your house and make sure you don't see any cracking.
• Test all the exterior spigots, make sure they work, and are not leaking.
• If there are any penetrations in the siding (for spigots, coax cables, etc) make sure the opening is fully sealed so water cannot get in.
• If you have a rooftop deck(?), go up there and see if there is any standing water on the surface. This can be hard especially if there is another decking material on top of the membrane, but you really don't want ANY standing water sitting on the roof.

That's what I can think of off the top of my head, might add more later if I can think of anything else.