Need a fresh Mind

[devildogcummins]

Problem truck is a 2007 5.9 auto with mods, I have been fighting the p2121 APPS code for at least a month now, replaced 2 APPS sensors, replaced gear indicater harness, and I am still getting a 1/2 volt spike very often which sets engine light and code p2121. Need a fresh mind to help what I need to look at, we havent rued out ECM but really doubt thats it. Any help would b awesome. Thanks guys

 

[TCDiesel]

Map Sensor? Intake Air Temp sensor? also the ECM takes sometime to learn the APPS status.

 

[devildogcummins]

How much time do u think, its not driveable at all pedal goes dead before u can even get it in gear. Im at my wits end and I dont wanna keep throwing money at it when Im guessing what it could b.

 

[TCDiesel]

Does the ramp Idle work on the steering wheel controls (Cruise)?

 

[TxDiesel007]

check all the wiring and grounds

just went down this road not too long ago.... turns out it was the stem of all my issues...

also check and see what other codes you retrieve.. anything to do with the FC?

 

[ForceFed]

I was running a cfm+ which angled the dipstick tube just enough to rub through the wiring and cause apps problems.