This has happened twice now, I would get a cel, but when I scan it nothing shows up. After a few days the cel would disappear?

Has this happened to anyone else?

 

Is it the Check Engine light or the Maintenance req light that you saw? If it was the CEL was it or did it flash or just stay on solid? What are you using to scan the code? If it comes on there should be something stored in the ECU of what triggered it.

 

go to a parts store --- not your cell phone app- for scanning the codes
They pull codes for FREE

as noted above- is it a cel or the mait req light- that one will flash at engine start when nearing oil change time, then come on solid when 7500 miles has been reached since last reset of the counter

 

have the parts store do a full electrical test = starter draw, alternator output under load, battery voltage and its ability to recover from load

bad ground cables can make weirdness too

 

It's the Check engine light that comes on and stays on. I have a obd-2 scanner and I've taken it in to get scanned and Autozone and O'Reilly's doesn't get anything either. Like I said though, it comes on for a few days then it disappears again. I'm pretty sure my battery needs to get replaced sometime soon but it's just weird that the cel would come on with no codes.

I haven't noticed any difference in the performance of the car or mpg's.

 

you suspect the battery, but didn't get it tested while at the parts store?

try that next~~

Or the theory of bad ground wire (there are several braided wire type from frame to engine and trans- one loose or crudded up could be the ground for the ecu
That would cause loss of power/signal to ecu intermittently, clearing whatever code is being thrown

Sometimes you have to think way out of the box, but combined with your thoughts on battery and certain symptoms....

 

Does your scanner show live data? If so what is the voltage? Monitor it.

Also, when you check for codes are you doing it with the CEL light on?

 

Fast Times; If you were buying a scanner today, which would be on your list? I see many recommends to go to the parts store, is that mostly to avoid the cost of purchase, or have access to a better model?
Thanks for you thoughts.

 

We have an older laptop that would serve well for a code reader. Is getting software and adapters for various vehicle manufacturers the way to go? Does software reset codes as well as a dedicated code reader?
I found this thread https://acurazine.com/forums/perform...d-know-898223/
anyone in 2 Gen tried this?
Thanks

 

because most people don't want to spend 100$ - $200 on a code reader to find out what a CEL is for,
We send them to parts stores which have at least a basic reader
and do it for FREE (in USA- others unknown)
shops will charge 1 hour or more just to get the codes and maybe tell you what the internet says they mean- without telling you that combination of codes along with your symptoms actually means =

Those who work on cars a lot, or are doing advanced tuning/racing/drivability diagnostics on cars tend to own a reader/scanner that has LIVE DATA you can watch during driving
Cheaper ones just extract the codes and have a reset button

I prefer to use the `CLOCK fuse remove 1 minute and reinsert method` to clear ECU
When you pull the secret backup power to the ecu- it definitely clears and resets- forces a full self test on startup
Overkill if reader has reset button? probably= but doesn't hurt to do

 

Thanks 01tl, I'm leaning to getting the software and dedicating an old laptop to the garage. We can run the vehicles with it on, if need be, but I'm guessing we'd mostly use it for scanning for codes. I'm starting to think that there will be more ready access to the software, I need 4 different manufacturers. Using the same machine for everything means a central storage device with all the data, and we can easily back that up to a desktop.
I can borrow Lastspec's if I need a reader, I was hoping to find someone here using a software package, preferably not from Alibaba / Ebay via Hong Kong.
Thanks for your post !

 

I'll check it out when it gets warmer, to cold in good ole Wisconsin to check it right now.