I've owned my 2500HD since new. Now has 151,000 miles. Always owned GMC/Chevy Trucks. Wouldn't have anything else. I had the crankshaft sensor replaced by a dealer at about 70,000 miles. Same symptoms are occuring again. I know where the sensor is located. Question is..how do you get to it to replace it? Thanks
Crankshaft Position Sensor Replacement on 2001 GMC Sierra 2500 HD
you have to get everything out the way to get to it.belt, pulleys, fans if neccssary. purchase a crank shaft pulley puller and pull the crank pulley. make sure everything in front of the cover is out the way and you can get to the bolts on the cover. remove the cover replace the position sensor
If it's an 8.1 liter, the crankshaft position sensor is on the back of the motor on the top by the firewall. Easiest way to change it is from under the truck. It's held in by 1 bolt.