2020 Silverado Brake Failure while towing

mdot · July 5, 2021

2020 Rocky Ridge K2 Silverado 5.3L

14K miles

First time posting.

Have been expereincing intermittent brake lights staying on after engine shut down for several weeks. Took it to the dealership, who ran a diagnostic on the truck and came back with "all things look normal, no codes". By the time I got home, the brake lights were in a state of constant "on" and I was able to restart the truck without applying the brake, even with the key fob outside the vehicle. Received several Onstar warnings to "Service Parking Brake". The parking brake had engaged and would not release. I disconnected the battery for 20 minutes, reconnected the battery which cleared the code. Called the dealership and was told I would have to leave it with them for awhile (several days to a week) to find out what the issue is. Would be ok except they do not provide a loaner car and rentals are thru the roof in our area ($100/day) so I have been living with this inconvenience until I can find an alternative way to work (80 miles rt).

Then this happened over the past weekend:

While driving back from the lake with my boat in tow, the truck went into a critical brake failure mode. Here is the series of events.

Moored boat at dock and went to retrieve truck to remove boat from water.
Could not unlock door on truck with FOB. Truck was "dead". No voltage activity.
Used 12v portable jump pack to start vehicle.
Let run for @20 min before proceeding to drive home with boat attached. Check engine light was on for 30 seconds then went out, but no warning dialog boxes.
After we were on the road for @15 min, in rapid succession, I received the following warning dialog boxes:
1. Service Trailer Brake System
2. Service ESC
3. Service Parking Brake
4. Brake System Failure - 62 MPH Top Speed
5. Check engine warning light
6. Traction Control Off warning light
7. ABS Off warning light

As soon as I saw this, I tried to apply the brakes and they went to the floor. As you might imagine, it was chaotic in the vehicle when it became apparent that the vehicle along with the 6000lbs of Boat/trailer in tow was not going to stop in any timely fashion. Along with the trailer brake failure and vehicle brake reduction, the backup surge brakes on the trailer would not engage due to the lack of quick inertia braking force. I had the pedal to the ground and eventually we came to a stop. The rest of the ride home (2 miles) was a 5mph white knuckle event.

The insult to the injury is there has been no warnings, email, text or posted on account from Onstar about this series of events but... I did get one on the same day that my Oil change is due. I am posting the screen shots I took after we came to a stop.

It is being towed to the dealership tomorrow. I will let you know what happens.

I absolutely love my truck. It is the 5th Chevy that Ive owned, and sadly the worst one of the bunch.

M

bshort · July 5, 2021

If I was throwing parts at it, I'd start with the brake switch and a reflash.

mdot · July 7, 2021

Update 07/06/2021

Delivered vehicle to dealership @7:30 am. Reviewed issues with intake service personnel and validated that they had received documentation of events and supporting pictures.

Service Advisor called me @ 1:30pm and informed me that they had identified the issue. They retrieved a p25a2 code and proceeded to re-program the BSM per 20-na-073 warranty code 28yn75386417. Had to look this one up. It is a GM Service Bulletin that outlines the Loss of Brake Assist.

https://static.nhtsa.gov/odi/tsbs/2020/MC-10175760-9999.pdf

I picked up the truck 10 min before they closed (big mistake) and was told that everything had been cleared, the vehicle road tested and was good to go. After gathering my wife, who was eye balling a GMC Sierra, we left the dealership and proceeded home. After @ 5 min, my wife called me (she was following me home) and let me know that my brake lights have been on the entire time since we left and wanted to know if I was riding the brake. I immediately turned around and took it back before I experienced another brake failure. This is now the third time it will be back to the dealership for the same issues. Im exhausted and disgusted with this whole process.

Any suggestions on the next move? Should I start the process for turning this turd into a lemon? How long should I be reasonable about this?

Thx

M

mdot · July 7, 2021

Updated 7/7/2021

Received call from Service Advisor and he stated that they found the issue. The Brake Module needed to be refreshed to relearn the brake pedal position sensor. I went to pick up the truck and when they pulled it up for me, the brake lights stayed on with no one in the truck with the engine still running. WTF!! They drove it back into the shop to rescan it and found no codes. Restarted the truck and the brake lights went off. I decided to drive it home and roll the dice. Stopped at Petsmart for some dog food and brake lights stay off when I turned the truck off. By the second stop (restaurant) the brake lights wouldn't turn off and now it sits in my driveway with the brake lights on till it drains the battery.

I am starting the process to lemon this one out. It will go back to the shop for the forth time in less than a month.

Has anyone ever been thru the process? I bought the truck new @ 7 months ago.

Thanks

M

mdot · July 8, 2021

Updated 7/7/2021

Called GM's Warranty, Repair and Lemon Law helpline and was given a case number. They will be assigning a Senior Advisor within the next 48 hours that will work with my dealership until this is brought to an acceptable resolution. I will post updates as this progresses.

M

Tahoe02 · July 10, 2021

I lemon lawed a 2015 Tahoe in Florida, do a Google search for the requirements in Georgia. Have good documentation and all service work orders. Also Google search Lemon Law attorneys, most will get paid when GM settles the case. I did not get much help from GM and I doubt things have changed in the last few years. Good luck and keep us informed.

mdot · July 11, 2021

Did some research and Georgia has 24mo/24K with an extra year to file for arbitration. Also, if it involves critical components or a safety related issue that could possibly endanger the occupants of the vehicle or others, it only has to happen once to qualify for Lemon status and I can bypass the usual 3 attempts to repair. I guess either way, since it has been to the dealership 4 times for this and next week will be number 5, I could file for the status now.

GM has already contacted the Service Advisor and will be discussing with me next week what the process towards resolution will be. I will give GM some time to work it out. Don't really want to give it back and not sure there is a suitable replacement availble in our area.

Will post updates when I get them.

M

Edited July 17, 2021 by mdot