Oh well, I tried really hard to give all the info that was needed. 'Nuff said, as I don't want to berate the original poster.

 

Where do you see PCM as all I see is ICM.....and I don't see in that picture where it shows the other end of the Wire/Cable ends up....by the picture it looks like it just disappears in to a shield.....If someone could just let me know it is appreciated....and I do apologize if I am misunderstanding or just not seeing something......Thanks

 

Never mind the drawing, the first image is the schematic, that's the one you're concerned with. It shows the PCM below the CKP sensor. Three wires go from the PCM to the CKP: purple, yellow, and the third one is actually pink, not green. That is battery feed to the sensor from the PCM. The schematic tells the connector and the pin locations. The PCM is located on top of the coolant reservoir.

 

I have to pay attention to the drawing as this is what I bought for a replacement and need to know where it goes besides just the sensor....

Engine Crankshaft Position Sensor Connector Standard

 

OK I'll give it one more shot......

I thought you said you had a 2000 2WD Blazer. This part is supposed to be for 1996-1999 with the sole year 2000 application being the Astro Van. I don't know the reliability of this info, but my source is:

http://intake-manifold.dvautoparts.c...w-jkjnlrrjqmrk

FYI the wiring and schematic I posted is for 2001 and should be the same as yours. No connector in the harness. Wires go directly to the crank sensor to PCM without any connectors. My advice, forget the scanner and what you think you know has to be the problem and do some rudimentary testing. You really need to change your mindset.

So why do you think the wiring is bad and the connector needs replaced? Is it because a code read with your scanner told you it is intermittent, and you have rationalized that the crankshaft sensor wiring or sensor connector or sensor must be at fault and causing an intermittent open in a circuit? I really doubt this. Could you have set the codes you are now reading by jacking with the sensor and turning the key on?

From way back in post #5....... Do you have steady spark at the COIL while cranking? To test this, disconnect the coil wire from the distributor and install a spark plug in that end. Now ground the body of that spark plug to the engine and have someone crank it while you are looking. If you have a steady spark across the plug gap, then your crank sensor, connector, and sensor wiring are all OK. Furthermore, your PCM is successfully triggering the ignition coil and the coil is capable of putting out enough voltage to jump the plug gap. If you have steady spark at the coil, you need to look deeper than the crank sensor and sensor wiring for the source of a no start. If you do not have spark then we can help you diagnose and that will be easy as there are not very many things to prevent it. You could even have a bad PCM setting crankshaft sensor codes and causing the running problems.

Bottom line. The first thing you need to know is if there is a real problem with triggering the coil to send a spark. That and the RPM is really all crankshaft sensors do (PCM reads the crank signal, drives the coil, and also uses the sensor info to know RPM). That will send the diagnosis in one of two completely different directions. It seems you are making this much more difficult than it really is through rationalization of bits and pieces of evidence without considering the whole. That is what we keep trying to tell you.

I don't understand why you ask for help, and then reject what we tell you and go back to your original premise. It's frustrating.

If I had to use the SWAG system for diagnosis ..... from everything you have said thus far, if the codes come back after clearing them - I'm betting your PCM is bad.

Les

 

I agree ^^^^ Between Les and I, you have almost 80 years of combined professional experience behind you


I totally agree on the wire harness in post #24.... it is not the correct harness.


At the CKP sensor: The pink wire comes from the ECM 1 fuse in the underhood fuse panel. Make sure both terminals on the top of that fuse show battery voltage when the ignition is in the RUN position, (do not remove the fuse while testing). The yellow and purple wires go directly to the PCM with no connections in-between.


One test that will tell you instantly where to start looking, is at the ignition coil. This requires a test light, not a DVOM. Connect the alligator clip of the test light to battery positive. Touch the test probe to the white with black trace wire at the ignition coil. Crank the engine. The test light must blink while cranking. Post your results.


EDIT: I'd bet bottom dollar that the PCM is NOT the issue here Those things are darn near bullet proof, and it would take some serious jumping of battery voltage and ground to very specific circuits to destroy it.

 

Good one Captain,

More definitive than my test for for telling if crank sensor and PCM is working. Eliminates the coil. I like it better. OP should do that instead. At least we both do agree that evaluating if the coil is being triggered, is where to start this diagnosis. As far as PCM being bad I admit I would prefer a bit more diagnosis before placing any monetary bets. That S.W.A.G. system of diagnosis is not very reliable without getting to do (at least some) appropriate testing.

 

It's actually quite a broad test, encompassing a lot of things. Basically checks everything except the ignition module and ignition coil, (two of the most common problems). Sometimes it's easier to work backward to the problem.

 

I was told By the online auto store that I bought this from that this is what I needed I had called and double checked this with them and they assured me that this was the correct part.....The only other one they had was one that you would have to splice the wires on.....I don't think that would be a correct way to fix this......The reason I believe this is the problem is because when I push in the plug and wires on the plug on the sensor in tight it will straighten out for a little while then as it settles and kinda pushes back out a little it will act up again.....and my crank sensor has a connector on it the sensor can be unplugged and removed but the other end is what I needed to know where it was located......again I apologize if I seem like I am defeating you your advice or misunderstanding anything at all I am not trying to do that as I appreciate all the help it just seems like every time I try to figure this out I hit a wall.....If this does not fix the problem then to the scrap yard or sale for a parts/Mechanics special.....Thanks again to all.

 

Thanks to all for the help but I am done with this truck it has developed a problem just sitting some how.....Something has killed the battery completely and I have no Idea what as it never did this before so.....its either a parts/mechanics special sale or scrapyard......again thanks to all for the help...