Tried searching on Forum and not much luck with transmission codes. 2003, 2500HD, 2WD, 5.7L, 91k mi. Seems to have 2nd, 4th, no lock-up. Does have reverse. CEL on w/i 1/2 mile after battery disconnect. First code was P 1790 for faulty shift. PO 755- 2C Solenoid circuit error PO 846- 2C...