boss just bought a 2003 2500. Was driving fine, and then hooked on to the trailer with the skid steer. pulled up to a stop sign and the idle went down to 500 rpm, and rough, then surged to 1000 rpm and tried to push through the intersection. didn't do it the next day, had codes 2121 and 2122 which are both to do with the apps voltage. I am not familiar with the automatic transmission, but am pretty familiar with the cummins

 

so whats your question? there is way to rest the apps. i dont know it by heart, but maybe you could look it up.

 

I am pretty sure it is an apps based on the codes of 2121 and 2122. I tried to replace the apps with one of the cheapo apps sensors from ebay(53031575), and I got no throttle at all. I don't know if there is a difference between the 2001 apps with a standard trans and a 2003 with an auto? Did I maybe not get the calibration right? I can't find any difference between the apps from year to year until 2004.5. Anyone have any advice on this one?