This may be of some use to you, just read the haynes manual for cherokee (I'm having issues myself with a poorly cherry and needin fault codes!)
for self diagnosis codes 1991-1997 models:
To display the codes, turn the ignition key on,off,on,off and finally on. the codes will begin to flash on the check engine light.the light will blink the number of the first digit then pause and blink the number of the second digit, for example code 23,the MAT sensor circuit,would be indicated by 2 flashes,then a pause (about 2 seconds) followed by 3 flashes. if more than 1 code is being accessed the pause between codes is about 3 or 4 seconds.
If this is what your trying to access and I've not missed the point I have a list of the codes in the manual and I'm pretty sure you could find them on the net! good luck