2006 cummins. For the past year or so I have had the error code p2121 coming up while driving. The truck kicks into limp mode giving me dead pedal for about 3 seconds and then the pedal comes back. If I drive the truck for over 5 miles with the code up without clearing it p2127 then comes up as well as p2121. I have noticed that the code has been coming up more recently when the motor is under a load or at speeds exceding 65 mph. I have checked the voltage on the apps sensor and it reads fine. The computer was reflased and the apps sensor was replaced but it didnt solve the problem. I have checked the wiring harness and didnt find any points of wear in the wire loom or signs of corosion on the connections. I filled the connections on the apps sensor, ecm, top connection on the cp3 pump and the connection on the side of the fuel water seperator with dielectric grease due to reading about those areas being common areas of issue with this problem but have still have the same codes coming up. The codes dont come up all the time. It seems like they come up about 1 to 2 times a month on average leading me to believe its not the ecu that is bad but a connection somewhere that i am not seeing that is causing this problem. Im running out a places to look and the dealerships recommend a new wire harness and ecm but thats a little out of the price range right now. Any ideas of where I am missing or something else that can be causing these problems.

 

sounds like maybe a bad connection or a broke wire