I had the same problem with my vehicross when I bought it. It has had the transfer case replaced and ABS control unit by the previous owner and neither fixed it. When you drive it around, it is basically like being in 4hi the entire time. Last week, I went in and bypassed the TOD and installed a switch and now I drive in 2wd but the check light still flashes. Is doesn't solve the problem but atleast it makes it where you can drive it.