OBDII link error
 

So yesterday went to clear the CEL light after replacing a bad coil that lead to a misfire. I just went to O'Rileys, as I've done many times before without issue, and the OBD reader could not do anything because it said, "Link error". Any ideas on what the issue is? :dunno:

It could be the reader, or it could be your car.

Given that you had a few looms apart during your repairs - and since you last had a working scan - its possible you have a blown fuse. Check F31 and F14 (behind the glovebox), as they both feed power to the OBD port.

Scanner was Orileys so know it works on other cars. CEL went away today after a drive. Guess Ill see if it comes back amd venture from there. Thanks for the replies.

Scanner from the loaner tool bin at the auto parts store is a high failure item. Just because they let people use it does not mean it works. It would be nice if it always worked, but it is likely to be abused. There are several data streams that come on different pins, it's possible -- likely -- that the data stream from your car does not work with the scan tool, but from other cars it works okay. You have to compare to a known good condition, then see if it also works with your car, or not. Just because the guy gives it to you does not mean it is reliable.

You can have your own scan tool for 30 bucks, give or take. Go on eBay or Amazon and get an ELM-327 module that works with your device -- phone/tablet. Then go on the app store for the device and buy an app. OBDFusion is a good one, TorquePro is another. There are free versions that you can use on a trial basis. Technically, you can use the free version for everything forever, but the free version has a limited feature set, the fee-based versions are the way to go.

You can read codes and reset the computer. The fee-based units allow you to collect data logs that you can feed into a spreadsheet and build a graph. The free versions do not support graphing.

Thanks for the info. The scanner was brand new (someone had just stole the other one) and the scanner only had an issue after I tackled the valve cover job. I ventured down there more than once trying to resolve the issue and used the scanner a bunch of times. In any case CEL is gone and I will probably invest in something like what you had mentioned.

A good quality scanner is one of those must have tools for a DIYer. They aren't cheap but well worth the investment for the long haul. Over the years have tried a bunch of scanners. Have the Torque app on my Seicane. Use it for realtime info and additional gauges. The go to complete scanner for BMWs only that I use is the Foxwell 14020sch. Very easy to use, intuitive.

Cool, thanks for the info. I agree and quality scanner, especially for a BMW is a must.