Originally Posted by Amelie
I think the most likely choice would be that it's a memory setting stored in the WJ from the previous owner.
"All WJ models feature one of three different types of outside rear view mirrors and either of two types of inside rear view mirrors. Basic WJ models include standard power operated outside mirrors. All outside mirrors have 3 manual detent positions, full forward, full rearward, and normal. Premium power heated mirrors, with and without the driver's side auto-dimming feature, are offered or included on other models. A memory system that automatically positions the power mirrors for two different drivers is included on most Limited and all Overland models. The memory system on 1999-2002 WJ's included both outside mirrors. Starting with 2003 model production, the memory function was dropped from the passenger side mirror."
I have seen it stated before where the memory function was dropped from the passenger side mirror but my 03 still has this feature. If you can call it a feature because it has also changed position from it set program.