Originally Posted by vwbuge
Gear 4 ratio incorrect.
Since your girlfriend's Jeep is an '02 with the 45RFE this info may be incorrect, but with the 4th gear ratio code it's showing a problem with that clutch pack. I believe with that tranny the 2nd and 4th gears share the same clutch pack so your girlfriend is probably noticing the harsh shift from 1st to 2nd and you're getting a code for the 4th gear ratio - but it's all the same problem.
If your scanner can get the CVI numbers while you drive the Jeep. There is a specific range each clutch pack has to be within; if they're out of range then I hate to say it but you're probably looking at a rebuild or replace.