I have the same problem. I have tested everything and it seems like it is probably the transmission unit. Any way to know for sure? This 4x4 is a 2003 with only 159 miles!! It still looks like show room condition. If I put it in ESP mode and start it in 1st gear and switch to 2nd right after it starts the display doesn't flash. I can go from 2nd to 5th, on the display it shows 5th but it isn't going in 5th, but when I shift down to 1st the lights all dim and within 3 seconds the display flashes with trouble code 5. If it's the transmatic is it really worth the money to fix it? I thought I read somewhere they go for around $2,000. Is that true?