MyGMC Trailer Light Test

Question

My GMC trailer light test functionality appears to have been removed or lost in the most recent update of the app - March 2025. I use this feature frequently. I called OnStar support today 3/9/2025 and they seemed confused regarding this trailer light testing feature. How do I get this trailer light test functionality restored in the app?

siochan71 · Answer

I too noticed this today. I connected to my trailer and went to run the light test in the app like normal and it is nowhere to be found. I chatted online with an advisor and they seemed to not know what I was talking about. They suggested I uninstall and reinstall the app. The trailering functions in the app were very helpful.

rcookie · Answer

Same here. No help at all.&nbsp;

chukkar · Answer

Helen,Thank you for the response. I’ve a couple of final thoughts to share. First, I find it interesting that a company that brands itself with ’Safety’ removes a proven proactive safety diagnostic feature that trailer users have come to rely on and that the reason for the safety feature removal is ‘speed’ of………..something, not quite sure what gets faster for me. Second, customer value, delivering value as determined by the actual customer is paramount to running a business. Take away or don’t deliver on what I value, then I don’t purchase or stop purchasing your product. This choice by OnStar removes a safety feature from the platform, a feature I highly value. It’s seemingly being replaced by an ‘enhanced’ user experience, but as the user I am at a loss for what really improved.&nbsp;I’ll move forward with cancelling my OnStar service.&nbsp;Cheers.&nbsp;

chukkar · Answer

I’m going to reach out to my dealership today to see if they can offer any insights. Additionally, I’m hopeful that OnStar will respond to these posted messages. The trailering features in the app were / are key to successful, convenient, and safe trailering using my GMC 3500HD truck. If this turns out to be a deliberate OnStar / MyGMC decision to permanently remove the trailering features from the app, after these features being operational for over 6+ years, I’ll be canceling my OnStart account.
I’ll post again after I speak with the dealership.

chukkar · Answer

Update: My dealership confirmed that this trailer light testing functionality was part of the MyGMC app and the features removal has nothing to do with the vehicle or its hardware. They gave me a GM customer number 800-462-8782 to call.upon calling, I was once again routed to an OnStar agent. The agent was able to read me an app revision statement that said &nbsp;‘they’ have simplified the app to improve the user experience and that the trailer light testing feature wasn’t coming back. With the agents assistance I was able to provide my feedback regarding this decision to remove this feature.&nbsp;I am anticipating a 3 - 5 day wait period for the feedback to be reviewed and a response to be sent back to me via my email address.&nbsp;I’ll update again after I receive my response. As I stated before, if the decision to remove this feature is final, then I’m going to simplify my user experience even further by cancelling my OnStar subscription and deleting the MyGMC app.&nbsp;