I think this has been posted before but i have now experienced it and have pictures to help!

Ok so i bought a used throttle pedal assembly for a spare. I plugged in to check it and low and behold I had a CEL even when the key was just on let alone engine running. So I grabbed the scanner and had a P0122-AP Accelerator pedal sensor ckt low input

So I looked at the data and everything looked good but TPS voltage was low at .37 volts. Truck came off idle and it operator normally but still had that CEL. So I check the computer for diagnostic info. it said that anything at or under .37 volts will set the light. So I pulled the assembly back off and started to check it out. Well I foudn the bushing on the opposite side of the TPS was backed out and allowed the shaft to **** side ways under the spring pressure. So easy fix put the bushing back where it belongs. Voltage went to .51 volts and the code went away!

Here are some pictures to help you see the issue
http://good-times.webshots.com/album/559819076QNBcVu

 

Good job Tim. I like a guy that drills on down to find stuff like that. Not many have the patience

 

thanks tim. had cel, flashing od light & code po221.all good to go now

 

Good work, reps sent. (at last).