Things You'll Need
The crankshaft position sensor on a Chevrolet 3.1-liter V-6 engine is designed to determine the position of the crankshaft in relation to the engine block and relay this information to the powertrain control module (PCM). The PCM uses this information to decide when to fire the spark plugs and to adjust the ignition timing. In order to accurately determine the crankshaft position, the crankshaft sensor extends five inches deep into the engine block.
Turn off the engine and shift the vehicle's transmission into park or first gear (manual). Engage the emergency brake.
Lift the front of the vehicle using the automotive jack and support it with jack stands. Place wheel chocks behind the rear wheels.
Crawl under the front of the vehicle and look up at the back side of the engine. The crankshaft position sensor is made from black plastic and has a two-wire connector attached to it. The sensor is located on the back side of the engine block, halfway between the oil pan and the top of the block.