Hi. A 2003 or below may require you to use the chrysler (CCD) connector and could be that it doesn't do 2003. Sometimes I just use the Obd mode and usually that works just fine. Hope this helps. Regards austin

 I diagnosed Jeep Wrangler 2011 using MaxiSys Pro and it was auto scanned but did not get a chance for Cherokee. Is OBDII communication working on Cherokee? Keep a cheap ELM327 tool with you to verify OBDII communication, e.g. one from www.scantool.net. It's not so cheap but as compare to MaxiSys Pro and better than other clone ones. You can use it also with Torque Pro software. Nowadays, OBDLink SX is on discounted price of US$ 29.95 and free delivery in USA.

Jeeps are covered under Chrysler, for diagnostics just select Chrysler instead. I have done many US market Jeeps with Maxisys with no problems.

 I've a situation like yours. I've done a diagnostic in a Jeep from 1999 and it works great! Support tell me that in some old Jeep is normal that have that kind of situations, it work better in new systems.

 Jeep is supported, and engineers are working on Jeep old cars.