Testing the cam sensor, inside the distributor on all 4.3L, 5.0L, and 5.7L GM equipped mini-vans, pick ups and SUVs, can be easily and accurately done with just a multimeter.
No scan tool required for the cam sensor test... since a scan tool is not gonna' be much help and a resistance test, of the cam sensor, will get you no-where... since the cam sensor is a Hall Effect type sensor that can not be Ohmed with a multimeter.
I'm gonna' show you a way to do it with just a multimeter, in Volts DC mode, that is so accurate, that you'll be able to say, ‘Yes, the cam sensor is BAD’ or ‘No, the cam sensor is OK’. And as you know... this is a time and money saver.
This article will also help you to troubleshoot the following diagnostic trouble codes: P0340 (Camshaft Position (CMP) Sensor Circuit) and P0341 (Camshaft Position (CMP) Sensor Performance).
If you need to know if this camshaft position sensor test applies to your specific 4.3L, 5.0L, 5.7L GM mini-van, pick up or SUV, take a look at the ‘Applies To:’ box on the right and scroll with the next button 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 cam sensor on your 4.3L, 5.0L, 5.7L engine.
Tools You'll Need:
When the cam sensor goes BAD, it will NOT keep your 4.3L, 5.0L, or 5.7L GM equipped vehicle from starting. Yep, that's right... your mini-van or pick up or SUV will crank up and start. Now, of course, it's not gonna' run right.
Here are a couple of symptoms that your vehicle is probably experiencing:
The very first thing you need to ask yourself, before testing the cam sensor is: Did the codes (P0340, P0341) or the symptoms appear after I replaced or moved the distributor?.
If the answer is YES to the above question then you need to read the next section...
In all of the years I've been working on cars (as an automotive tech), the number one cause of DTCs P0340 and/or P0341 has been that the distributor was removed and installed... but not synchronized correctly.
If this is the case in your specific situation... then you have found the solution to your problem (and diagnostic trouble codes).
You'll need to synchronize the timing marks on the distributor and the crankshaft pulley/ timing cover so that the rough idle, check engine light and trouble codes can go away.
You'll need to use a repair manual (or a Google Search) to find out how to install the distributor correctly... since I don't cover any remove and replace info in this article.
If you haven't removed the distributor at all, then this article will help you... since it sounds like the cam sensor is BAD... and I'll show you how to test it.
“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