Where oh where is my crankshaft sensor?

My mechanic used a hand-held pc to find that my crankshaft sensor has malfunctioned. This he plugged in under the dash to get this diagnosis. I drive a 99 dodge durango 8 cylinder 5.2 SLT 4wd. where is my crankshaft sensor? How do I replace it?

What your mechanic did was find a code that says that the PCM believes that there is a problem with the crankshaft sensor signal. There is no code that say part X is bad. The proper procedure is to follow the manufacturer’s troubleshooting flow chart for that code. It will lead to tests to verify the wiring between the sensor and the PCM, then to check the sensor, and lastly to suspect the PCM.
Of course, you can take a chance on it and just throw a new sensor at it. There’s probably at least a 50/50 chance you will be right.

Some scanners not only pull diagnostic codes, but some can do real-time monitoring of various engine management components. And with this type of scanner you can indeed monitor the output signal of the Crankshaft Position sensor.

By the way, the Crankshaft Position sensor is located on the transmission bell housing, drivers side.

Tester

You are trying to install the part yourself to save money, that’s being a smart shopper but, not in this case (IMOO). Problem #1, you don’t know what to look for. Problem #2, after you install the part the check engine lamp may still be illuminated. This would require another trip to the shop to hook up the diag tool to clear the code. After discovering you installed the part the shop may charge you to clear the code.

This is the replacement procedure from ALLDATA…

The sensor is bolted to the top of the cylinder block near the rear of right cylinder head. The sensor is accessed by removing the right front fender liner.

Remove right front tire and right front wheelhouse liner.
Disconnect crankshaft position sensor pigtail harness from main wiring harness.
Remove two sensor (recessed hex head) mounting bolts.
Remove sensor from engine.
INSTALLATION
Position crankshaft position sensor to engine.
Install mounting bolts and tighten to 8 Nm (70 in. lbs.) torque.
Connect main harness electrical connector to sensor.
Install right front tire and right front wheelhouse liner.