I know, older thread, but here is the home mechanic fix:
Confirm that the wire is chafed or broken at the AGS motor connection. Mine was confirmed at the dealer, who charged me $350 to splice the broken wire because they could not get a new harness. It lasted a couple months. To do this at home, you need to remove the front bumper cover. Not as daunting as it seems, once you find the 2 hidden screws, but there is nothing online for doing this on a Gen2 Volt, so here it is:
1. take out all the screws on top and bottom of cover. Make a note/take pics of which go where. The screws in the bottom of mine were varying lengths soi I just kept them in order of removal.
2. take out 3 screws and 1 push plug from the front of each wheel well.
3. remove the "hidden" screw that connects the top rear corner of each side of the cover to the body panel above it. This is the one everyone misses. It is a 7 mm and not easy to get to with a ratchet. You can access them from the wheel well.
4. pull the cover outward on each side/. I used a large flat blade screw drive inside the driver's side wheel well to help pop the clipped area free. Passenger side pulled right out.
-Be aware there is a large wiring harness connector on the drivers side that needs to be unplugged so don't let the cover just fall.
5. Remove the AGS. You will not see the harness until you remove the 4 screws that hold the AGS in place and remove it. Then it's pretty apparent, but there is not much slack in the wiring so don't let it fall.
5. Install a new Active Grille Shutter Harness. Mine was $43 from (a different) dealer and of course, it was the wrong one. It looks like there are 2 versions of this harness. The ONLY one the dealer says exists is 84433963. This one has 5 wires going to 2 separate connectors (3 to the AGS motor, 2 to something else(?)). Probably a sensor on the Premier version as mine is an LT, even though I gave them the VIN and they confirmed its an LT. The problem is the upstream connector doesn't plug into my car's wiring harness. it only has 3 wires. My OEM AGS harness part# is 047984-002 but the dealer says that is not a GM part#. Whatever. I ended up splicing my old harness upstream connector onto the new harness (in the vertical section of the harness with heat shrink butt end connectors, tubing, and electrical tape), ignoring the extra 2-wire plug (wrapped it up in plastic). I also packed the trouble area where the 3 wires go into the AGS motor plug with marine-grade silicone. Hopefully it will keep the wires from chafing again.
location of "hidden" screw in the upper rear corner. One on each side. access from wheel well.
Bumper cover removed.
Found the problem. The wire splice the dealership did sucked and did not last
"Wrong" part# on invoice. OEM label on original wire harness with an invalid part#
cover removed
Original upstream harness plug
upstream plug on new/wrong harness
my Frankenharness