Tranny Codes

I know this has been written about before, but I just want to get a take on my specific situation. My Check Engine light came on randomly the other night. I cycled the engine five times and it went away, as would be expected. I drove it fine for a day and then it came back on again. This time I pulled the codes. P0700 and P0705. Here is what is going on with my tranny. My backup lights do not work anymore. I imagine this is due to a blown fuse. I also have trouble starting the engine in park, however this is extremely random and I cannot figure out what triggers it. This has been going on for over a year now. I imagine this is due to the NSS. The third and most concerning problem is that when I put the tranny in tow (1-2, 3) it will either not change modes at all (i.e. acts like it is in drive and does not downshift like you would expect and does not stay in gear all the way through the rpm range) or it will change modes but will immediately shift to first gear. This has only been going on for a month or two. I'm hoping that my transmition controler isnt fawked, but it probably is. Any advise would be great.

Every single symptom you listed can be caused by a dorked up NSS. P0700 means a transmission error code has been set. P0705 is "Transmission Range Sensor Circuit Malfunction (PRNDL Input)". That would be the NSS. The trans computer also uses the NSS to figure out what gear you've got the shifter in. Fortunately it's pretty easy to clean the NSS and here are a few good writeups.

http://jeepin.com/features/nss/index.asp
http://www.go.jeep-xj.info/HowtoNSSrebuild.htm