Forum Discussion
sjdraper
4 years agoNew Contributor
attached device may be preventing your vehicle's diagnostic test
I have been receiving from on-star "an attached device may be preventing your vehicle's diagnostic test from completing. Unplug any devices from the diagnostic port and try again later." Car w...
Advisor_Kaitlyn
4 years agoContributor
We recommend first uninstalling/reinstalling your app as it is a quick troubleshooting step. If that does not remove the error message, pushing your blue OnStar button will connect you with the Technical Teams who are the most knowledgeable and helpful for issues like this. There may be internal errors that only they will be able to resolve. Be sure to mention that you have already taken your car to your dealer for this issue because they may also recommend that.