I'm not sure how they connect or where in the CRD. But having over 12 years experience modding VW diesels I can say there are other ways of tricking the computer into fueling more. On a VW installing a simple resistor and tricking the fuel temperature (also known as an EVRY mod) would achieve significant gains and sometimes cause a limp mode if too high a resistance used. It is quite possible that something similar is installed on your Jeep. Look for any wires that may have been cut into, particularly anything related to fuel pump or fuel temperature sensors. I'm not sure where they are on the CRD as I have not needed to play with it. Typically a Tuning Box connects itself across the fuel pump connector. It could look very stock if done properly. Ask Keith to review your stock maps and see if anything looks out of place. He should have it on file, or you may still have it on your computer.
2007 WK CRD QDII, GDE HOT tune. 275/55/18'' on Sahara's, SRT8 suspension.
2000 Jetta TDI (hers)
2006 Liberty CRD (sold)
3 VW TDI's (sold)