I own a 1999 jimmy that has a push button 2hi, 4hi, 4low and auto 4X4. It has 144000km and every time I try to switch to 4hi, 4low or auto 4X4 it just keep flashing but wont change. I can feel and hear some noise under the chassy only when I hit 4low but nothing els seems to happen. Any help here befor I go to the dealer and get a bill for $150 just to tell me what needs to be changed. Thanks in advance, John in NS Halifax.

I had the same problem. Turned out that the transmission control module shorted out... the dealer couldn't explain why it happened or if it would happen again. About $900 later it was fixed.