XJ Transmission Codes and Problems

[LILGREENXJ]

Ok everyone I will try to include all needed information and make this as short as possible. I am aiming to get some technical information to repair me jeep.

Make:Jeep
Model: XJ Cherokee Classic
Year: 1998
Automatic transmission 4wd stock everything besides a 3" spacer/shackle lift kit and 31's

I am getting multiple diagnostic trouble codes but the codes in question are as follows:
P0740 Torque Converter Clutch Circuit
P1899 P18XX Manufacturer Controlled Transmission

I have a used transmission that I am getting ready to swap in but i don't know if i am wasting my time. I just want to make sure that I'm not wasting my time swapping in the "new" one.
I got the jeep for a good deal and i just picked up the transmission for pretty good deal too. I just have to wrestle it all in now i guess. just seeing if some one knows that the solution i am trying will fix my problem or not.

 

[transman731]

the 1899 is a code for the neutral safety switch, the 740 is for the tcc system.
the 1899 may inhibit tcc so i would suggest trying to figure out the nss code first.
the nss code can cause trans problems of all kinds, you would probably kill yourself if you wrestle that trans in only to find out it was a nss

 

[LILGREENXJ]

Thank you transman. I will definitely check the nss first. I will report my findings I'm hopes of helping the next guy.