ok so i noticed i was not recieving the signal to fire the coil from the pcm so i swapped out the crank sensor and the truck started a little rough but it started then died so i messed around in that area some more and the truck started right up abd ran real good. so i backed out the driveway and went foward about 500 feet died. i hook a light to coil harness plug and get no light except a faint flash after i let off key and motor winding down.i have good 12v at asd side of plug i can ground light to battery and turn engine over with light on. can someone explain how to check the crank sensor circuit? i have checked it over and over and seems fine to me maybe im missing something?

 

The crankshaft position sensor has 3 wire... one is power from PCM, one is ground through PCM and the other is signal to PCM. The power from PCM should be 8 volts. If you are getting 12 to the sensor, its probably cooking the sensor. That would be a PCM issue if the internal voltage regulator is shot. But to test the sensor, hold the sensor connector with the retaining tab pointed up and put an ohmmeter across the middle and far right terminals. There should be an open reading.

 

ok just so i get this right open reading means i should get 0ohms?

 

Yes it should

 

ok so i measured the resistance all i have is a good ole fashioned needle tester no digital but it it works good i get a reading of 3 with ohm setting xxyy and 5 with 10xx these r the 2 settings for reading ohms on this meter not sure wich one is wich.

i also get a reaiding of 2 ohms when probing ground to battery and grey black wire at pcm is this normal or is this a short to ground?