I bought this truck with code P0357 and found the #7 coil connector had been changed and one of the wire connector was broken. Also replaced the coil, boot, and plug while I was in there. I soldered the wires together, cleared the code, but the code came back immediately. My next step will be to exchange the #5 and #7 coil to see if the problem follows. Could the ECM be bad if the problem stays at #7?

 

Yes...it wouldn't be the first time that happened to someone here.

 

If the problem stays with #7, disconnect that COP connector and with KOEO, grab your DMM and see if you have battery + voltage at the red wire, harness side.


If you do, pull the fuel pump fuse and connect your DMM between battery + and the pink/light blue wire harness side and crank the engine over. If the voltage jumps between battery + and ~1 volt while cranking the control side of the COP is okay.


If not, unplug the PCM connector and measure the resistance of the #7 COP connector pink/light blue wire, harness side and pin #78 of the PCM connector.


If the resistance is over a couple of ohms, repair the pink/light blue wire.


If the resistance was near zero, plug the PCM back in and with the KOEO, measure the voltage of the pink/light blue wire at the #7 COP connector, harness side.


If the measured voltage is near battery +, the Pink/light blue wire is shorted to power someplace with in the harness.


Otherwise, the PCM is suspect.