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Posted

On my 2015 GMC sierra with 54K on it. Out of nowhere the message "service brake assist" is intermittently going on and off. brakes seem fine. Anybody have this issue and what did dealer do to fix it. any feedback is appreciated

Posted

How nice of your truck to display a warning message!  My vacuum pump was going out and produced the hard pedal/no power brakes, but I was not so lucky to receive warning from my truck.  

 

Try and pump your brakes a bit while you're rolling slowly or at idle and see if you can get the pedal to go hard.  Warning, you wont be able to stop as easily once it goes hard.

 

Take it in to your trusted dealer and they'll have it back to you in a day or two with a new vacuum pump.  You should qualify for the extended warranty on the part and have the work done on GM's dime.  

Posted

I am lost here brake assist is different from brake booster. You guys are going to scare the 5hit out of the man. Haha.

Sent from my SM-N960U using Tapatalk

Posted

Thanks for the replies. This is the craziest thing. message was going on and off like crazy yesterday on my way home from work.  shut truck off when I got home. Took the truck out later last night and to my surprise, no messages.

 

Today I put 50 miles on it and also had no problem and no message. brakes feel fine. checked brake fluid and its dead on. going to take it to dealer tomorrow to see if they can figure it out. I'm thinking a bad electrical connection

wanted to use truck on my vacation but not feeling great about putting a ton of miles on it if I have an issue. I'll post what they tell me

  • 2 years later...
  • 2 months later...
Posted (edited)
6 minutes ago, Jay Blanchard said:

OK folks, I just started getting the same problem. This morning, I finally started getting the "Service - Brake Assist" warning on the dash. I checked, and found there to be a recall for this. See recall #N192268490

 

https://static.nhtsa.gov/odi/rcl/2019/RCSB-19V645-6988.pdf

 

 

 

Is that a add on device  because of cylinder deactivation? An external vacuum pump? I’m asking for a friend.😳

Edited by KARNUT
  • 10 months later...
Posted

My 2017 sierra has the same problem and the brake does get extra hard but only at low speeds like if I'm parking in a space and trying to creep forward. Never have a problem any other time and it's very intermittent.

Posted
On 9/28/2022 at 3:24 AM, Ronnie Jones said:

My 2017 sierra has the same problem and the brake does get extra hard but only at low speeds like if I'm parking in a space and trying to creep forward. Never have a problem any other time and it's very intermittent.

This is certainly not what we like to hear, Ronnie Jones.  Please know, customer satisfaction is extremely important to us. Our team would be more than happy to take a closer look into the concerns with your 2017 Sierra. To do so, please send an email to [email protected] with ATTN: Ronnie Jones/GM Trucks in the subject line.

Please include your contact information, VIN, a brief description of your concern, and the name of your preferred dealership. We look forward to hearing from you. To learn more about GM’s privacy policy, please visit https://www.gm.com/privacy-statement.html.
 
Privacy Statement | General Motors
Your privacy is important to General Motors. This Privacy Statement addresses the personal information GM collects and how GM handles that personal information.
www.gm.com
 

  • Haha 1
  • 3 weeks later...
Posted

I have the same problem as Ronnie Jones. At low speed (like in parking lots) the brake is hard as rock. Brake works just fine on the highway. I love my 2015 GMC Sierra. It has 322K and still purr like a kitten. No one seems to have an answer to this brake issue. I don't want to start replacing parts if it is not going to fix it. I looked into recalls but for some reason my VIN is not included in the recall. I saw posting someone replaced the vacuum pump that fix the issue but also someone else said that did not fix the issue. 

Anyone know the status on the lawsuit? 

https://gmauthority.com/blog/2020/03/lawsuit-filed-over-alleged-brake-booster-problem-in-general-motors-trucks-and-suvs/

  • 1 year later...
Posted

I just starting having this issue after coming back from a 11 hour trip. I got the "Service Brake Assist" alert. I dismissed it but the brakes were running hard. What has everyone done to fix this issue?

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