Greetings,
I have also experienced this fault myself, 2002 2.5 CRD Cherokee, on startup a small red light illuminates an the bottom lower corner of the dash, next to the rev counter, and i have found no mention of it in any manual, i did however also have a problem with the ignition switch at the time, it wasnt always switching on, and the key seemed a little loose to turn, after replacing the ignition switch, the fault no longer occured, my guess was that this light was perhaps coming on due to some electrical fault/back feed caused by the faulty ignition switch, i did not find the purpose of the light, but do know that manufacturers do use parts, e.g. dash circuit boards, which can be fitted on other models and again guess, this could poss serve a purpose on a US spec vehicle?