ecm issues usually throw lots of random codes so I dont think I would be quick to jump to that conclusion just yet. Can you describe what your symptoms are exactly. Are you describing dead pedal?
Remove that ATS ground it should not be done... You need to test the alternator and fix the AC noise issues and not modify wiring and electric system as a bandaid to a real issue. Filters, adding grounds, tinfoil are all signs of a bad alternator diode(s). Remember these truck ran 10-12 years WITHOUT this extra ground why does it need it now? Maybe because something failed? Do you fixed or bandaid it?So did apps re learn this evening and still same issue. Temp out side was 32 f and engine cold with com box off had plenty of Fp 15 to 12 and had same bucking issue. Issue seems to get worse as engine temp and length of drive increase. If I drive for say 1 hour condition gets really bad and will throw p0121 apps low voltage and also. Over voltage code and coolant temp code. But this is only if you stay into throttle when the bucking/surging is going on. Vp only has 59000miles on it. I have also re grounded apps sensor like ats says. When truck was a auto this took care of the tc cycle issue. Have since installed a nv4500 with no issues
Opps... ECM is dying...Is a new apps. Has maybe 500 miles on it. Now got a p0606 ecm code and intermitten oil pressure and coolant temp