False P0300 code in Vortec engines.

[Roy French]

I recently started getting the flashing ck engine light, P0300 code in my Chevy truck with a 6.0. It happened at random times under different load conditions. The thing is it was not miss-firing. One time I was pulling a 12,000# trailer up a hill with no power loss. It turned out it needed a crank sensor relearn/calibration. You need the scan tool to do this, but it’s real easy. You have to set the calibration up on the scanner, then floor the accelerator pedal with the engine running. (The scanner controls the engine speed so you don’t over rev.) 3 seconds later no more logging miss-fires. I’m not sure what caused it to go out of spec. It may be that the sensor is on the side of the engine block where excessive rust occurs. It’s possible the rust could move the sensor away from the crankshaft tone wheel slightly.

Topic