Re: 02 grand cherokee
Welcome to the garage.
First of all, which engine transmission do you have? Are there any driveability issues, or does it all seem to be normal?
Both codes have to do with the line pressure of the transmission. The line pressure is the regulated presssure inside the transmission, which is used to apply the clutches. If the pressure is really low, the clutches will start slipping and burn. (P0867 = Line Pressure Fault and P0868 = Line Pressure Low)
Did you check the fluid level already and did you smell the fluid for burnt smell? Is the fluid nicely red in color, or dark brown?
When you tell first which engine/transmission you have, i maybe can give better ideas what is going on. It can be something easy as a faulty line pressure sensor or even a shorted wire to the line pressure sensor, to something more serious internal in the tranny. You better not drive it further until you know what is going on, to not burn a clutch unnecessary.