Lost my keys so I went to wrecker got a different steering column with new key, truck won't start and a buddy told me to switch out the ECM from that wrecker truck into mine and the new key would be recognized and problem solved, before I do this cause it's a non returnable part I was hoping to get some confirmation here that this is the route I should take, the truck does turn over fuel pump is working just won't fire.

 

No that wouldn't work on a 2006 North American Ranger

We have a bit of an issue with the type of Ranger you have, in the UK they had North American models AND what we call International models, which are different

You list a 3.0l engine so I will assume its a petrol engine, 3.0l Vulcan so a North American Ranger

PATS, passive anti-theft system, was used from 1999 to 2008 in the 3.0l Rangers, it uses transponder keys, so vehicle would not start without correct key
In 2006 PATS was in the Digital Instrument cluster(HEC), not the PCM(ECM) but..............cluster and ECM are a matched pair along with the transponder Keys
So you would have to change cluster(HEC) and ECM and both would HAVE TO BE from 3.0l Ranger 2004 to 2008

Its not hard to program new Keys to the PATS if you loose all the Keys
You need a laptop computer and software like Forscan, to "talk" with ECM and Cluster to add 2 new keys, or 3 or 4, but TWO is minimum
You also need the OBD2 cable to USB interface for laptop
LONG thread here on how to add PATS keys: https://forscan.org/forum/viewtopic.php?t=839
Goes all the way up to 2021 so updated

Forscan Software is not expensive and cable should be available locally, you would still need to get your current key duplicated(cut) so you would have 2 keys to add to PATS, not Cloned, must be new key with different number than current key

Many Mobile Locksmiths have this Ford software and can come out and cut New PATS keys and add new keys to ECM/Cluster, at vehicles location
So ask the price of this

Swapping ECM and Cluster can also run into issues with other modules in vehicle, in 2004 Rangers got the CAN BUS data network, so not really a simple answer to just do the swap, if it doesn't work then you NEED a Ford Dealer so they can use "official" Ford Software to re-integrate all the modules in the vehicle