P0335 - 8.1 chevy, 2004, what can it be

Question

replaced crankshaft sensor and plug, plus cam sensor. still will not start. also no rpm on gauge when cranking . battery is new and up full charge. have 12 volts to reference, and 12 volts between reference and low reference. have some signal from ckp sensor signal , have no way to read ac signal out put. found bad wire to low reference at plug that is reason for plug replacement. need help as I am stranded in campground.