If anyone has a second to review the attached datalog I would appreciate it. I am using the Moates Xtreme ALDL and TunerPro RT to capture the data. The problem is, every few seconds many of the field readings just go haywire for a second. I have checked all the grounds and connections and cannot figure out what would be throwing everything off. The same anomaly occurs when using my autoxray hand scanner, so it's not the cable or software. Any suggestions would be greatly appreciated.

 

SES-CE light occuring during event or randomly while driving? I am thinking ECU ground?

 

Yes, usually just during idle (on breifly). I have checked all the grounds so many times I can't even count them. With that said, I keep going back and checking, with no change. I even changed many of the connectors and checked continuity (even using schematic to make sure not to miss one). But I agree that's what it sounds like. I was just hoping someone might have something I haven't thought of yet. Thanks for you input.

 

There is a servicce bulletin out on GM wire harnesses that at 20-25 year old regarding inevitable failures. That was posted in CHP magazine a few years ago.

 

Thanks for the heads up, I will run more continuity tests and see if I can narrow it down. As you notice, when the readings jump around they seem to be a select few. I wonder if there focusing on what they have in common could help diagnose the particular area to be looking. Thanks again.

 

I am having the same issue as you. I get blocks of bad readings myself. I notice that on the bad rows the battery voltage reading is 0. I am thinking that it has to be a data logging issue and not an issue with the ECU.

BTW I am running the APYPWB MAF 6E Linear wideband mask and logging definition file.

 

A friend of mine is having a similar problem:

https://www.thirdgen.org/forums/diy-...t-datalog.html

Maybe try a redundant ground to a known source, first on the ECM and then another on the block if that doesn't work?

 

Looks like Joe's computer is doing the same as this one:


What did you find that was causing the problem?

 

I will go out this week and install a temporary ground and see if that resolves the issue. I know it is not a datalogging issue, since it happens with my autoxray hand scanner as well. I will update as soon as I very all common grounds.