I replaced the passenger side valve cover gasket and had to move the injector cable bundle around. After putting everything back, I started the vehicle and immediately got the engine image and "Check gauges" lights. I checked for the code with on-board display and an external OBD-II reader and got P0118:> "High Voltage" and it will not permanently clear via any method. I went ahead and replaced the ECT, but code still appears, with thermal-meter needle burying itself in the hot zone and that's even with an overnight, absolutely dead-cold start. I checked the two wires for abrasions to short, but found none from the plug, to the crossover bundle. I then separated the two wires from the plug and still got said code. Can anyone out there help me? I'm pulling what little hair I have left out. Remember, the code/condition did not appear until I removed the breather and shifted the injector connections bundle, so I could replace the passenger side valve cover gasket. P.S.> Truck runs just fine, except cooling fans come on immediately, {duh}.

 

After getting no response for this thread, I decided to wing it. I went to a salvage yard and cut off what looked to be good ECT sensor wires with plug, all the way back to the crossover bundle. I cut my wire just above that point and spliced the replacement on. That did the trick. I can only assume that even though I couldn't see a break in either of the two wires, or plug, one of them must have had a break. Moral of the story; even if you can't see it, things can still be broken.