What exactly are you referring to when you say that you had it re-mapped?
I've never heard that terminology before.
I've also never heard of a Commander's VIN being run through FCA's website and coming back as a Grand Cherokee - that is extremely unusual. I'd say follow the steps below on the link provided and see if you get the same results stating that it's a Grand Cherokee:
To get the factory build sheet for your Commander, click on the link below and navigate to "Your Vehicle" click on "Equipment Listing" and then enter your VIN number in the box that says "VIN" and hit "Search". The factory build sheet will list all of the factory options & optional preferred equipment packages that your vehicle had installed from the factory when it was built.
the VIN bit first, i ran mine(the VIN not the actual jeep) through
vindecoderz.com (i cant post links yet so try puting 3 letter w's in front of it front of it
a mate on another Jeep Board, UK based, ran it through one he uses, and it again came back as Cherokee. that was quite worrying and also useful.
worrying in so far as if ordering Genuine Mopar bits the Vin number would be potentially misleading, but since its basicaly a cherokee anyway no real danger.
the bonus useful bit though is that all the European spec commanders have DPF's fitted - the cherokees dont. thats useful incase i decide to tune it up further by removing the DPF - i could always argue that it never had one fitted due to being a cherokee.... also its a big fine if you get caught having removed a DPF from the original vehicle build - due to exhaust emission standards, but since mine according to the VIN is a cherokee - "take it up with Chrysler Jeep officer, i didnt build it i only drive it" (if ever pulled over by a policeman with an emission tester)
the remapping is probably called something else on your side of the pond -have a look at
i cant post links so have a look at celtictuning.co.uk
basically a techie type plugs a laptop into the OBD port and changes loads of software settings - mine pre remap idled at 800RPM after the remap it idles at 500 and accelerates like the wind (ok, a 2 ton not aerodynic wind) so on idle speed alone a fuel saving.
forgot to mention another repair i did using a straw from the burger chain with the upside down W logo, draining the passenger footwell when the rubber bung thing got blocked, so i cut the end off and replaced it with the straw.