First, check that none of the 4WD control buttons are stuck in or halfway in. With the H3 on, try cycling through the different modes. But often this might be an ABS sensor issue, anything from mud in the tone ring to a failed sensor to a damaged lead wire. I had this coming on last month on and off for a couple of weeks and it went away. I was about to buy new rear ABS sensors as my first troubleshooting step since the front ones are pretty new.
But if the left front tire isn't actually low (drive it for a bit to turn on the TPS, they go to sleep when stopped) then the first troubleshooting step is always the H3 battery, connectors and cables when there are mysterious issues related to anything electrical.
As I think about it, ABS is the more likely issue between the 4WD buttons vs. ABS. If it's the 4WD buttons and/or encoder motor, usually you'd only get the Service 4WD message.
It happened on my H2, it turned out the wiring harness fell a bit and was laying on the tranny and wire got hot and melted. That was one time, the other time it happened to me it was the clutches in my tranny 4, 6. Yes, its happened 2x to me, I rebuilt my 6l80e to a stage 3 tranny now its bulletproof.
There are soooo many errors that will cause those 3 messages to show. You need a a full diagnostic scanner, not a cheap $10 BT adapter with an app. I discovered my steering wheel position sensor as throwing my code.