Testing the 24X crankshaft position sensor (located behind the crankshaft pulley/balancer) or code P0336 (24X Reference signal circuit) is an easy test that only involves a digital multimeter! You don't even need a scan tool (although a scan tool is a very handy tool to have).
The test that I'm going to show you is a dynamic test done by hand cranking the engine. If you're looking to do a resistance test of the 24X crank sensor, forget about it... such a resistance test for the 24X crank sensor does not exist.
The only way to test the 24X crank sensor is in action (as the engine is being manually cranked)... and this article will show you how.
If you need to know if this 24X crank sensor test applies to your specific 3.1L or 3.4L GM vehicle, take a look at the ‘Applies To:’ box on the right and scroll with the arrow buttons to see all of the applications.
Here are the contents of this article at a quick glance:
You don't need any expensive tools to test the crank sensor on your 3.1L or 3.4L V6 engine.
Tools You'll Need:
The most obvious symptom of a BAD crank sensor is the check engine light (CEL) lit nice and bright and the following diagnostic trouble code stored in the PCM's memory.
Below is a simple list of more specific symptoms that accompany a BAD crank sensor:
The most important thing to remember, is that when the 24X crank sensor has failed, your car will still start and run (although it may not run great).
“For instance, on the planet Earth, man had always assumed that he was more
intelligent than dolphins because he had achieved so much —the wheel,
New York, wars and so on —whilst all the dolphins had ever done was
muck about in the water having a good time. But conversely,
the dolphins had always believed that they were far more
intelligent than man —for precisely the same reasons!”
The Hitchhiker's Guide to the Galaxy