Onstar doesn't work all of a sudden; flashes red light

opeg1979 · January 17, 2019

Hello,

New to the site but have been lurking here before. Been looking around and can't find any good information on the situation so I wanted to post a question.

I have a 2015 Silverado LT Crew 4x4. A month or two ago I noticed this faint red (more like orange) light flash on the rear view mirror. I know the red light means Onstar is not connected but in this case it flashes very quickly. I push the buttons and nothing happens. Then I noticed the compass in the infotainment is empty and the dash shows N all the time. I called Onstar and they tried to connect and couldn't. They said we cannot connect to your vehicle please take it the dealer. Well I don't go to the dealer if I can help it. So I have been doing some research.

Now here is the thing that has me concerned...in October of last year I installed a Rough Country 30" light bar. No problems, it works fine, but I really can't remember if this Onstar issue was before or after that. I looked in the manual about Onstar stuff and found in there "Dont add electrical equipment" it could effect Onstar etc. etc. Is this really my problem? I disconnected the light bar and Onstar doesn't come back, I have checked the fuses that are linked to Onstar and they are fine.

Has anyone seen this type of problem? Is it pure coincidence that the Onstar problem happened after I put on the light bar?

Is there a way on the truck to reboot Onstar?

Any help would be appreciated!

Thanks,

Justin

jhplak325 · January 17, 2019

Common problem is the OnStar antenna leaks. I would start there

tbarn · January 17, 2019

^^^ x2

rmrgored · January 17, 2019

I had the same problem that I kept telling the dealer about the leak. Now my OnStar doesn't work. I'm going to replace the antenna but I'm afraid of dropping the headliner. Any tips?

tbarn · January 18, 2019

It's not hard. First of all , you don't need to drop the whole thing. Just the front. Remove the left "A" pillar molding, sun visor, sun visor anchor, left assist handle and the upper console. There are two screws under the flat trim plate that holds the switches. The plate snaps down ( plastic pry tool ). Remove the two screws and pull the console down.That will give access to the cables and antenna bolt.

SS502 · January 18, 2019

14 hours ago, tbarn said:

It's not hard. First of all , you don't need to drop the whole thing. Just the front. Remove the left "A" pillar molding, sun visor, sun visor anchor, left assist handle and the upper console. There are two screws under the flat trim plate that holds the switches. The plate snaps down ( plastic pry tool ). Remove the two screws and pull the console down.That will give access to the cables and antenna bolt.

When you say left “A” pillar molding, and the the left assist handle is that the same piece or is there two? Thanks for the tip too, I would not want to drop the whole liner ?

tbarn · January 18, 2019

Left assist handle is above the center of the door opening. 2 different parts.

SS502 · January 18, 2019

58 minutes ago, tbarn said:

Left assist handle is above the center of the door opening. 2 different parts.

What year are we talking about? Okay, I feel like an idiot...went and looked, just found it right where you said it would be, one on the passenger side too! I never even noticed them being there ? so thanks once again!! I was thinking the A pillar handle (installed after purchase) but learned something new ?

JimCost2014 · January 19, 2019

6 hours ago, SS502 said:

What year are we talking about? Okay, I feel like an idiot...went and looked, just found it right where you said it would be, one on the passenger side too! I never even noticed them being there ? so thanks once again!! I was thinking the A pillar handle (installed after purchase) but learned something new ?

Your statement was fine, and I see you are becoming an expert with the thumbs up, thumbs down emoji!

opeg1979 · January 23, 2019

Thanks for all the replies guys. if this is the case then why does Sirius XM still work fine?

opeg1979 · April 11, 2019

Update on this. I got a new antenna. When I took off the old one I did not see any signs of water and I am not surprised given the fact that I live in AZ. I quickly realized i got the wrong one, because it was missing the XM connector. Anyway, I plugged it in and it did not fix the issue. So doing more research I think I found the next best possibility. Onstar has a backup battery, and I read that if you disconnect your backup while the key is on or the dash lights are on it triggers the backup battery to engage as if the vehicle was in an accident to contact Onstar. This may have happened by me or when Walmart put in a new battery in the truck I am not sure, but that seems to be a logical possibility.

sniperxxx · June 3, 2019

so how did you fix it? mine did the same thing when i changed my battery. just 4 days ago....Im pissed cause i dont want to spend money at the dealership just for changing a beat 3 year old battery.

ive got a 2016 sierra 1500 slt 4by

changed battery and all of a sudden onstar stopped working and myGMC wont connect to the truck. light is red on the mirror.

they told me same as you....take it to a dealership to have them look at.

this must be a common problem they know of.

opeg1979 · July 25, 2019

I'll be honest I have not found a solution, cause it is not a top priority. I can't find where this so called backup battery is at and don't want to start tearing into it till i find some good info on it. I think its behind the radio screen though. Maybe someone on here can confirm? Just had my battery replaced again (batt. last 2 years here in AZ) so now i have a new fresh battery I will start looking into it more. Lately, i have not even seen the light flash or i just keep missing it! I hope we can find a solution, its just annoying when stuff doesn't work even if you don't use it! My main reason to fix is i like the mobile connectivity stuff like remote door locks specifically.