[jheat]

I hope that I came to the right place. Trying to determine how to fix my wifes 2013 Malibu LT 2.5 L. First the MyLink unit went out completely. It would occasionally power of and come back on by itself. Now it is completely dead. The other issue I am seeing is when I connect my scan tool up to the OBD port, it immediately starts pulling the codes even without a key in the ignition. What should I look for? How can I troubleshoot this issue? I don't have the money to take it to a dealer/repair shop. The car still runs but I would like to resolve the issues before they become worse.

Any help is greatly appreciated.

 

[repairman54]

Deal with what codes are stored first. Engine-codes.com is a good resource for descriptions.

 

[jheat]

So what if the electrical issue is causing whichever codes it is logging? It seems to me that the OBD port communicating without a key in the ignition should be a symptom of something. Could it be a short in the steering column or ignition switch? Is it a possible issue with the ECM? Is it the OBD wiring harness? The car is running fine and the code that it has is calling out an oxygen sensor. I'm more concerned about the electrical issue at this point.

 

[repairman54]

P code scan will only read powertrain codes. You also have B , C and U codes that a P scanner will not read. For example U codes relate to how CAN (Computer Area Network) system is communicating with all the modules in the car including the Mylink system. There are over 25 modules in the CAN system. For example my Tahoe has 41 modules in it's system.
I'm sorry to say that you need a high end scan tool that has the ability to read all the codes to properly diagnose any electrical / electronic issues to help determine which module is affecting the system and which module is not working.

 

[imidazol97]

I didn't go back to recheck, but I think I noticed that I did not have to turn the key to ON
when I plugged in my Acton to read from the ALDC. When I plugged it in, the unit started
reading.