If you are using a test light, then yes. And you will have to back-probe the connection. You likely will not be able to have this connector unhooked while also having the engine running.

 

I checked for ground and got nothing. Will I have to drop the pan to check the range/ pressure switch, or can i check the wires at the PCM? Could there be a loose connection in the pan or is it more likely a bad switch?

 

I checked and have power at plug connecting to trans (pink wire). If it has power to switch , is there anything else that could cause it not to work. Other than a bad switch.

 

In the case of D4, Channel A should read open (no continuity to ground) and channels B & C should read closed (continuity to ground). This is with the engine running and the shifter placed into the appropriate position. These values are best monitored with a capable scan tool.

If all of the wiring checks out from the ECU (under the dash) to the range/pressure switch, then the switch is the most likely culprit.

 

Thanks to those that offered information and ideas. I finally went into the to check the pressure/range switch. i replaced the switch and wireing harness. Once together, shifted like a champ. Have all gears now. Now on to the next item on the list to fix.