I wish Jeep wouldn't use "Gateway Control Module 'A'", or "GCW" (how they get that I don't know) for pre-2018 (JL) Jeeps. It gets confused with the Security Gateway Module, which prevents doing much with the CAN bus unless properly bypassed. But I digress...
The Gateway Control Module is also known as the Totally Integrated Power Module, or TIPM. You'll have much better luck troubleshooting if you focus on the TIPM. But in this case, I don't think it's the TIPM.
The thing to keep in mind is that the same DTC can be set by different modules. It's the same fault, but where it comes from is important. Since this involves the sway bar, U0447-Implausible Data Received From Central Gateway is actually a different set of troubleshooting steps than if it were set directly by the PCM. In this case, the TIPM is getting confusing CAN bus messages from the Automatic Sway-Bar System (ASBS).
Possible Causes
ASBS CAN BUS DTCS
ENGINE DTCS
AUTOMATIC SWAY-BAR SYSTEM (ASBS)
All things point to the Automatic Sway-Bar System. The good news is it's a common problem with the ASBS. Well, maybe not "good" news, but the fix is relatively easy.
1. Locate the ASBS connector near the sway bar.
2. Carefully separate the connector and check for water, corrosion, bent pins, or other signs of damage. This connector is in the worst possible location as far as environmental effects, so it is likely the cause. Even though the connector is "sealed", water can and will get in.
3. Clean and/or repair and/or dry out the connector.
4. Clean the socket and the pins with contact cleaner.
5. Reattach and check if the problem goes away.
If it does, you aren't done yet...
6. Disconnect the connector again.
7. Apply dielectric grease in the connector cavity. This will properly seal the pins against water and help prevent corrosion.
8. Reconnect and never worry about water intrusion into the sway bar connector again!
When I saw all of the sway bar issues out there, it was one of my first connectors to get dielectric grease. I have done several more since, mostly as I do other preventative maintenance. I'm happy to say I haven't had a problem with my sway bar, and my Rubi has made many deep water crossings.