I have a TCM w/ a K25L, just over 2200 hrs. Sporadically i get codes for the acc pot and throttle motor. using the Hitachi hand set i can watch the ETC sensor 2 spike voltage up to almost 4 volts when it malfunctions and MIL sets, idle is all over (hi/lo).
According to schematics ETC has six wires that go to large plug on ECM, and six from APS to small plug on ECM. I have tested all 12 wires from part to ECM they are all good. Grounds test good. I have replaced; ECM, APS pot, ETC motor, ETC relay. What am I missing? When it works it runs fine, there is no common event that sets code (ie; hot-cold-humid-dry etc)