The crank position sensor in the 2001 Chevy Blazer supplies an electrical signal to the truck's on-board computer, indicating the crankshaft's position in degrees of rotation. The computer uses this signal to synchronize the fuel injection and ignition systems. Common symptoms of a failure in this sensor include engine stalling, its inability to restart until it cools, if at all. Replacement can be accomplished in under an hour and requires only basic hand tools.
Set the parking brake and chock the rear wheels. Lift the front passenger-side wheel off the ground. Place a jack stand under the lower control arm and lower the jack until the truck is resting on the stand. Disconnect the negative battery cable from the battery.
Slide under the front of the truck and unplug the electrical connector on the sensor. Use a 10mm socket and ratchet to remove the sensor retaining bolt that secures the sensor to the side of the timing cover. Twist and pull the sensor until it slips out of the cover.
Apply a small amount of silicon grease to the seal on the sensor and push it into place in the timing cover. Reinstall the retaining bolt and electrical connector.
Reinstall the battery cable. Raise the Blazer off the jack stand, remove the stand and lower the truck to the ground. Test drive the car to verify that the repair fixed the problem.
