07 trail blazer will not start code P1516-P1682 bank 1 bank5

Question

codes state P1516 TAC module throttle actuator position performance Replaced (TAC) still nothing P1682 Electronic control (ETC) voltage incorrect. Replaced fuel pedal Module still nothing .Checked voltage don't the correct voltage . Have 5 volts and 7 volts and 2 lines with battery power is this correct on (TAC) side and (ETC) side

Answer 1

P1516 Throttle actuator control (TAC) module throttle actuator position performance

P1682 Ignition 1 Switch circuit  2

P1516 is set due to the voltage difference of ignition 1. Even with a P1516 the engine start, it would go into a limp home mode and you can reset the TAC by restarting the engine. The cause of the no start is  P1682 if the engine does not start. switch 2 circuit power other circuit from the ECM Start with the EC relay and the fuse. in the engine fuse relay box you check for power to fuse listed as ECM and ECM I. just to be on the safe side check all fuse listed as ECM and IGN for power, When P1682 set, there no way could of set a P1516. unless the injector fuse went open, or there is no power going to a PWR/TRNS relay. Try this take the cover off the EC relay turn the key on it should switch close,if it does not use a non metallic probe or toothpick and and close its contact, If you hear the system turn on switch out that relay.what commands the relay on is ground commands from the ECM.  Use this relay to test out the PWR/TRN relay.