2021 Chevrolet Trailblazer electrical system problems

“Dear Chevy, I am reaching out to you again because I am desperately requesting immediate assistance with my vehicle, which has now become an extremely serious and dangerous safety concern. On Friday, [XXX], I had my vehicle towed to the dealership because of the ongoing mechanical issues I have been experiencing. I was advised that the repairs would cost 877, which included a battery replacement and new sensors. I paid for these repairs and picked up my vehicle on Wednesday, September 2, 2026, believing that the issues had finally been addressed. Unfortunately, within approximately one hour of leaving the dealership, my check engine light came back on. When I arrived home, the key became stuck in the ignition. I immediately contacted the dealership and requested to speak with a Service Manager. I made this request approximately five separate times, yet I was unable to speak with a Service Manager until Friday, September 4, 2026, when I finally spoke with Matt. The situation has now escalated into an extremely dangerous and potentially life-threatening safety issue. On Sunday, [XXX], while driving on the [XXX] in Chicago, my vehicle completely shut off twice…”

“I am submitting this report regarding my 2021 Chevrolet Trailblazer because it has been experiencing the "Shift to Park" issue described in the GM bulletin 19-NA-206. Even when the vehicle is shifted into Park, it intermittently displays a "Shift to Park" message and does not recognize that the transmission is in Park. This issue has been ongoing and has not resolved despite normal use of the vehicle. It is frustrating to deal with on a regular basis, and it appears to be the same condition addressed by GM in Technical Service Bulletin 19-NA-206 that is available to view on the NHTSA website. I believe the NHTSA should push General Motors to issue a recall for this problem rather than relying on a Technical Service Bulletin. The issue appears to affect many GM vehicles, and owners should not have to bear the burden of repeated repairs or diagnosis for a known defect. I respectfully request that the NHTSA investigate this issue further and require GM to provide a permanent remedy through a recall.”

“The infotainment system which controls the radio,backup camera, onstart,and other safety components stopped working i took it to a gm certified dealership and it has just been all bad from there. gm has horrible customer service and so does the gm certified shop in michigan city i took my truck in that I only had for 11 months because the infotainment center went of paid for two diagnostic tests they still couldn't] find the issue and now they they're changing me 1,037.76 for a radio which they dont even know if it's going to fix the problem which if it doesn't then I have to pay more money for another diagnostic test and more parts and because I got mad and said I'm paying for a guessing game the dealership told gm that because I had some aftermarket equipment in my vehicle that that caused the issue bullshit the stuff never got plugged into anything at that point the day of my appointment with the audio shop the screen went black with no sound they're all full of shit and didn't want to take responsibility for the widely known issue with the telemedic system”

“My 2021 chevy trailblazer rs is experiencing issues with the infotainment system and the onstar module they have stopped working and I have no backup camera and this issue is a safety concern to me and anyone who rides with me i have contacted both gm and onstar and got nowhere with them after I had a diagnostic test done on 6/18/26 they recommended replacement of the whole system”

“While driving on Thursday, June 4, 2026, the vehicle experienced a sudden and complete failure of the electronic braking/power brake assist system. Simultaneously, multiple safety warnings illuminated on the dashboard display, including a persistent service wrench icon, a traction control warning light, and a lane-keep assist indicator light. Due to the loss of brake assistance, the vehicle was unsafe to operate and had to be towed/driven directly to a licensed dealership for emergency diagnosis. The dealership technicians subsequently inspected the vehicle and reported that the entire electronic braking system had suffered a total failure and is completely non-functional. Despite multiple technical service bulletins and recalls issued for similar vehicle builds regarding electronic brake boost interruptions and mechanical brake vacuum pump failures, I am being forced to pay for these critical safety repairs out of pocket. A sudden loss of braking power poses an immediate crash hazard, and I am filing this report to urge the NHTSA to investigate why this manufacturing defect is not covered under an active safety recall for this specific vehicle configuration.”

“Intermittently I will receive a dashboard message reading “shift to park” after I park the vehicle and do shift to park. This is a known issue with this vehicle across several years identified as “a known issue caused by a faulty switch in the shifter assembly failing to detect when the car is in Park”. GM has identified and found a solution to this problem by replacing the entire shifter assembly at the owners own cost. This malfunction has the potential to cause great harm. Potentially the vehicle could roll if the engine/system does not identify that it is in park. This could cause very expensive damages or even take a life. The vehicle also remains in accessory mode which drains the battery and can become even more costly for the owner at no fault of their own.”