I'm sorry I'm a little slow on the up take,,, I have read that you can start the re learn by ..... key -on , hd. light sw. -on , off , on, off.. then, key off.
My cherokee is a 4.0 , 1993 ... Does this sound proper to re-learn the mapping?

 

Just remove the battery cables then put them back on.

 

Just getting involved in the operation of the Old school processor.. Service Manual calls it SBEC (engine controller), Now its PCM (MPI) system... and DTC's Whew, when will they stop with the renames...
So, to read the codes (engine check flash) turn the key ON,.... OFF, ON, OFF,..... ON.... in 3-5 seconds. So now the PCM flashes code back to you... with spaces in between sets of 2 digits. BUT cannot CLEAR the codes just read them...
The book says you need an adapter connector with the PCM cable (square 6 pin) in order to reset them, that way OR, Disconnect BAT.
Ok... removed neg cable ~ 30 sec. did clear codes.... I had a 22 and 51 and 55 at the end of the runout. after clearing reading codes = 12 (+12 volts) and code 55 = completion.


Thanks for the help.
Still looking IF there is a key ON, Headlight SW on, off seq. to initiate re-learn... (I read it in the forum, somewhere).

 

As my grandfather used to say, live forever, learn forever! By the way, he also has Cherokee 4.0. Glad it worked out for you, had a similar problem