It is in "limp mode". It is a fail safe built in to the transmission. You get second gear and reverse. That is it.
There are a number of causes for the transmission to go into limp mode.
Mine turned out to be a bad TCM. Transmission Control Module. My OD off switch also did not light up.
I lucked out on finding my problem without having to take it to the dealer for a diagnosis.
I also lucked out that I have an 04 auto, and so does a friend of mine.
The 03 and 04 have the TCM separate (on the drivers fender) from the main computer. (behind the battery).
The 05 and 06 autos have the TCM integrated with the main PCM computer.
After checking all my connections to the TCM and transmission, I swapped in my buddies TCM. Everything went back to normal.
I found a couple 04 TCMs at salvage yards and had them shipped to me. One for a back-up.
So far so good. That was about a year and a half ago.
You can cycle your ignition key on and off three times, the third leaving it on, but not starting it. A code should pop up in the odometer.
Mine was just a generic PO700 code. The dealer said I needed to scan it with their fancy DRBIII reader to pinpoint the problam, for a charge.
I would start by checking and cleaning your connections to the TCM.
Good luck. I hope you find your problem inexpensive.
Know anyone with an 03-04 auto?
Here is a pic of the TCM on my drivers fender when I did the swap with my buddy.