Eric,
If it's an IOTA DLS then you have a 2-stage converter/charger. If the converter/charger is attached to the back of the Load Center (breaker/fuse panel) then it can't be upgraded to a 3-stage because there isn't a connection port to plug in the IQ4 smart-charger upgrade.
If the IOTA converter/charger is located separate from the the Load Center, then there "may" be a connection port to plug in the IQ4. The connection port looks like this:
Bob
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2016 GM 2500HD 6.0L/4.10
2018 Jay Flight 24RBS
2002 GM 2500HD 6.0L/4:10 (retired)
2005 Jayco Eagle 278FBS (retired)
1999 Jayco Eagle 246FB (retired)
Reese HP Dual Cam (Strait-Line)