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Old 10-04-2019, 12:34 PM   #1
afisher9
Scooby Newbie
 
Member#: 397954
Join Date: Aug 2014
Chapter/Region: MAIC
Location: Central PA
Vehicle:
2015 STI Launch Ed.
WRB

Default COBB1 Code

Hello everyone. So I feel like I have a somewhat interesting situation with the COBB1 code and after reading the other couple of forums on the topic I can't quite nail down what's going on.

So I have a 2015 STI with a turboback, intake, FP, Injectors, and flex fuel. I got protuned at the beginning of June and have had no issues with my car until last Thursday. So last Thursday I was driving home (about a 2 mile commute) and my car threw the COBB1 code. I made it home did some research on it, and basically the information I could find was saying that I needed to disconnect the ethanol sensor, clean it and plug it back in and see if that works. So I did, everything was fine until the next day when I then was driving home from work after filling up (e85 around 76% ethanol) and then after running another couple errands it threw the code again. So again, went home checked the wiring (everything seems fine to me), unplugged and plugged back in. This time I then called COBB and talked to them about the problem. Basically they said it could be a number of things and they need me to datalog every time I drive and catch it happening while datalogging to be able to send to them. Okay sure, makes sense. So I did that Friday night a couple times, all morning Saturday, datalogging and driving and no problems with one exception Saturday morning when I was not datalogging before starting my car.
Here's the interesting part though. I've noticed on Saturday and then again yesterday (Thursday) that if I turn the car into the "On" position as to turn the electronics on and start my datalogging before actually starting the car, I never have a problem with the code coming back. However, there have been two instances (one Saturday and one 5 days later, last night) that if I get in and start my car BEFORE datalogging the car will start up fine but within a minute throw the code. So of course, I didn't catch either of these times because of just force of habit getting in and starting my car before logging and going. But last night I did see a low of 0.1V on my left TGV, which according to my tuner is out of the range (0.5-4.5V) that would cause the code to be triggered. But as soon as it went low, threw the code it immediately went back up into the acceptable range and remained steady and fine. According to COBB's troubleshooting tool it seems like the 0.1 reading, if there isn't an issue with the wiring, would be an issue with the ethanol sensor itself.

So I guess my big question is has anyone else had this issue with it only happening when you are not logging? I also drove around last night and this morning while logging before starting my car and resetting after the code was thrown last night and have had no issues. So it seems like any time I try logging before starting my car I never have the issue which is just prolonging how long it is before I can send a log to COBB when catching the code being thrown for them to be able to diagnose further. But anytime I start my car before logging it throws the code almost immediately.
I am almost out of gas so I'll be filling up on 93 for my next fill up so even if it throws it's still set for the 10% ethanol it defaults to when thrown, but does anyone have any experience with this? Or do I need to just continue to log every single time before I drive and just hope the code throws while I'm logging? It's not the end of the world but it's annoying, especially if there is some correlation to my logging and the code being thrown and it's not just some weird coincidence. Maybe it's the sensor? Maybe it's the battery? (Stock battery with 45k). I originally just thought it could've been bad gas or something once it didn't come back after a couple days but after it threw the code again last night I'm thinking that might not be the case.

Any help is appreciated. Thanks!
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Old 10-17-2019, 12:14 PM   #2
afisher9
Scooby Newbie
 
Member#: 397954
Join Date: Aug 2014
Chapter/Region: MAIC
Location: Central PA
Vehicle:
2015 STI Launch Ed.
WRB

Default

Update: Was finally able to get the COBB1 code to throw while I was logging. Sent the log over to COBB. The TGV left voltage dropped to 0.1 for about 30 seconds. Determined that the issue was the flex fuel harness and had to be replaced. Did so and haven't had any issues since. Apparently COBB switched the harness to a newer version 2 (AP2) sometime this year with their flex fuel kits and if you have an older one it may have similar issues to what mine did. Pretty straightforward fix though. Just a heads up for anyone throwing that code. Hopefully it helps someone else out!
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