A little background...

85 4runner with the drivetrain from a 2000. The 2000 is (was) a 2 wd auto. I user the Inchworm adapter to mate my duals. ORS wiring

I've had the code from day 1 but, new kid, new house and, a job in finance during the depression has kept me busy.

I replace the neutral safety switch. Problem remained. Worked through This chart http://www.watrd.com/work/cip1780.pdf to find my voltages to the computer were a mess. the voltage is correct on the line corresponding to the gear your in. For instance, if the shifter is in low, the voltage for L is correct. But, the voltage on the other gears climb through the roof.

I'm terrible with wiring and electrical in general so, I apologize in advance if this is a newbie question. Could it be as simple as a bad ground?