98CherokeeLimit4x4

There is a jeep i'm probably going to buy next week.So heres the problem the guy said its a automatic he said that it won't go into first if its in drive put will if you put it in 1 st gear on the shifter and then put in drive once you get going???

BuckB91XJ

That is a "limp" mode that the AW4 auto tranny goes into. The good news is that mechanically your tranny is fine. The problem is the TCU-Transmission Control Unit (computer that controls your tranny) isn't working. The fix could really be as simple as reaplacing a fuse. You could also find a TCU in a junkyard donor XJ and pick it up for a few bucks. Definitely verify the fuse is good and that you have 12vdc on pin C15 of the TCU connector before you spend the money on a new TCU.

98CherokeeLimit4x4

Thanks alot so trans is fine how much would a tcu be?

BuckB91XJ

I forgot to tell you one thing. The PO told you to start in 1-2 and shift straigh to OD. Don't do that. You have to fully manaul shift it through all of the gears. As long as you start in 1-2 and shift it manually, you can drive it like that fine. Just don't ever forget and start from a stop in OD. Because the tranny will slip like crazy and that will ruin it. A new TCU from Chrysler I'm sure would be outrageous. Don't buy one new. Any 87-90 XJ with the aw4 auto tranny will have the same TCU as your 88. At a junkyard I wouldn't pay more than $20 for a used TCU.

JeepingDan

X2 and nice pic!

swnp101

I don't mean to thread-jack, but I'm having the same problem with my XJ.

Check out my post to see what I've done (and what kind of help I've gotten) to possibly give you some ideas on a fix.

https://www.cherokeeforum.com/f2/auto-shifts-4-500-rpms-11008/