I just had one question, when you were checking for a short to ground on the 5v refs why did you not check them against the other pins? Especially the pins labeled grounds. Just don't know if I missed you saying you did this or if it is a wasted step I do. Thank you
Around the 1 hour mark.
Also was wondering what you considered actually shorted. I had a tech checking a circuit and he thought the computer had failed. The reason he thought this was the diagnostic procedure for the fault told him he should have no continuity to ground on the signal wire, well he had 41k ohms. This would change to open load when computer was unplugged. I told him that I would be more worried about 100 ohms or less. So we did some checking and found the procedure is just not specific. There was the same 41k on all sensor signal wires. Real issue was the sensor lost its 5v ref and threw a fault for a short to ground. Thank you again
wnrwade wrote: I just had one question, when you were checking for a short to ground on the 5v refs why did you not check them against the other pins? Especially the pins labeled grounds. Just don't know if I missed you saying you did this or if it is a wasted step I do. Thank you
If I still had the sensors plugged in, only then would I have measured the 5v ref compared to the sensors grounds like in this series.
I think to measure the 5v ref wire for a copper to copper short would be a waste of time. There is not one incident I can think of where a harness had a copper to copper short where is was not also shorting to ground with some major damage to the harness. I suppose in theory it could happen, it just doesn't. I also believe you would have other symptoms pointing you in this direction. Also, the customer complaint and the order of failure of this system was a factor in our approach too. I really wasn't ever worried about the harness.
As far as what I consider a short? Most sensors I've measured are at least 1000 ohms between the ref and ground or signal circuits.
In that two part series I just linked you will get a better idea of what I am looking for.
So in short, I want to see more than 1000 ohms between any reference circuit and ground or sensor ground
Don't be a parts changer!
The following user(s) said Thank You: Tyler, wnrwade
Thanks for the info. I just seen a video where you are getting into the cordless tools. One tip I was going to give you was on the batteries. Snap on had a lot of batteries fail under warranty. About half that were sold in kits. What they found out was tech's were charging one right away and then using the other right away until it was dead. The one being used right away was the one that would fail. So when you get a new battery you should charge both before use. My dealer already charges both that are in the kits and he has seen an almost complete drop of failures in the first year.
Thank you again for all you do and the knowledge you provide
It was nice to go back and see that one again. I didn't quite follow that procedure when it first came out. I was disappointed that the PCM had already been changed in part 2 (no fault of Paul's), because I was hoping he would have elaborated more on the results of the test.
Watching it now with a better grasp of the material makes much more sense.
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I've been fascinated with that test ever since I saw the video. Thanks, sir!
