Re: 2006 Escape XLT
I'd phone Penn anyway and inquire about any possible coverage. ABS sensors aren't inexpensive. Most run around $100 plus installation. The trouble is that (not Escape specific here) some ABS sensors are connected directly to the wheel bearing/hub assembly and in some rare cases the whole unit has to be swapped out (gotta love new technology).
As jtugfestiva mentioned, a bad ABS sensor can initiate a 4WD service light as the central computer module controls how the AWD functions and if a few things (such as bad ABS sensor) interfere, it'll change how the 4wd system operates letting the PCM to believe that there is more than one problem when in fact, it's just one problem affecting another system.
'11 Ram Quad Cab 4x4 SXT 5.7L HEMI (stock); 48,500m
'06 Pontiac G6 GT 3.5L 220hp; 64,000m
'12 Chrysler 200 Limited 3.6L 283hp; 28,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!