I just picked up a 1990 Trooper with a known issue. The "Check Trans" light comes on intermittently. I've done some research on my own and figured out I could pull the DTC from the computer. I was able to pull the DTC codes, I got code 12 (as expected) and code 33. As far as I can tell Code 33 indicates that the transmission control module is reading a force motor current draw greater than 1.5A indicating that the Force Motor (EPC) circuit is shorted to battery voltage. In your experience, how reliable is the computer at pinpointing check trans codes? For my first attempt do I pull the auxiliary pan and replace the force motor?