1997 XJ, 4.0, AW4, etc. etc.

A little background, couple weeks ago driving down the freeway my check engine light came on. No big deal, got to my destination, Checked the code with the key on off on off method but don't remember what code it gave me. Disconnect the battery hoping it would go away, did not, drove home and on the way home it went into full retard mode, stay in 3rd gear, etc. Got home, checked the code with my OBDII scanner and got a P0100 which we have determined does not exist for this rig (more on this in a second). The next morning went for a drive, CEL was still on but shifted perfectly normal. Drove in to town, CEL was on but shifted normal. Parked it for the day and that evening when I got in it to drive home the CEL was off and it drove perfectly fine.

I have checked the codes with the reader a couple times since then with the CEL not on and still get the P0100 code and when I try to clear it I get an error with the scanner. I think this may be a whole seperate issue but who knows.

Tonight, driving home and doing about 10mph in construction traffic and the light comes on and instantly goes into retard mode. I can manually shift it through the gears, appears to be going into all of them, shifts a little hard but that could be cause I'm manually doing it, but the TC doesn't appear to ever lock up. Drove home, did the key trick and only shows code 12 and 55 which have been there since day one. Checked codes with the scanner and still only shows P0100.

I'm willing to bet that tomorrow or the next day the light goes away and everything is fine for a while again. I hope it stays on so I can go to NAPA after work and see if their scanner shows me anything different.

Anyone have any ideas?

It's just a sign that you need to buy that super duty

In the last week it lost a heater core and egt probe.