2024 GMC SIERRA 2500 Engine Problems

I own a 2024 GMC Sierra Denali Ultimate 2500HD diesel that has been out of service for 52 days due to an oil cooler / service bulletin related failure. The vehicle is under warranty. The required replacement part is on national backorder and, as of today, has not shipped. The current estimated ship date is February 17. During this time, neither the dealership nor GMC has provided proactive communication. I have had to repeatedly contact them for updates. This extended inability to repair a critical component, combined with the lack of parts availability and communication, raises concerns about the reliability of this system and the manufacturer’s ability to support safe operation of the vehicle in a reasonable timeframe. The truck is my primary vehicle and is intended for towing and transportation. Being unable to repair it for nearly two months due to parts unavailability presents a significant safety and reliability...

Complete engine failure with no warning on major road in heavy traffic. Very dangerous situation to pull off safely. Vehicle was towed to dealer and confirmed engine is seized. Unknown cause at this time. Transmission has had valve body replaced prior to engine failure. Transmission still has shudder after valve body replacement and prior to engine failure.

Constantly having to clean the map Senor to be able to drive pickup without service emissions alerting me to clean the map Senor or my truck goes in limp mode. This can’t be normal to have to clean this so much. My truck is fairly new and should not be having these issues. Put a scanner on my GMC and the code says P122D. I got on YouTube and I found MANY people complaining about my exact problem for quite some time!

The contact owns a 2024 GMC Sierra 2500. The contact stated that the vehicle was idling roughly, and the RPM fluctuated between 500 and 1,000 RPM while idling. The check engine warning light was illuminated. Additionally, the contact stated that the fuel economy had decreased to 13 miles per gallon. The contact stated that upon scanning the vehicle, the contact retrieved DTC: P0606 and P062B. The contact related the failure to GM Campaign Number: N232415860 (Fuel Injector Flow Rate Compensation). The dealer was contacted and informed the contact that a fee would be charged for a diagnostic test. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 70,000.

024 GMC Sierra 2500 Denali Ultimate, which has suffered: •Five catastrophic engine failures at highway speeds. •Total brake failure, leaving the truck unable to stop. •Severe electrical malfunctions, including flickering headlights at night. •Retaliatory actions from General Motors after I refused to waive my legal rights. I have documented proof, including GM’s own service records, emails, and a 7-minute recorded statement from GM’s highest-level technician, confirming that GM installed the wrong computer module (1500 series instead of the required 2500 series) in my truck. Additionally, I have evidence that GM executives instructed technicians to conduct diagnostics, take apart the engine, and reassemble it—but NOT repair the defect—after I refused to sign an affidavit waiving my rights. Due to these failures, I suffered a dislocated shoulder in one of the incidents, and my [XXX] daughter remains traumatized to this day. Given the immediate danger this defect poses to other GMC Sierra...

Vehicle surges and stays at 1700 rpm in low range four wheel drive when accelerator pedal is touched Dangerous situation if someone or something is in its path. Dealer is aware of the problem but is unable to repair, says it is inherent on those vehicles for the last couple of model years. (i can't safely hook up a trailer in low range 4X4)

The contact owns a 2024 GMC Sierra 2500. The contact stated that while driving 30 MPH, the check engine malfunction and Electronic Stability Control system malfunction warning lights illuminated. The contact was inadvertently locked out of the vehicle and was unable to open the tailgate. The contact disconnected the battery to cancel the warning lights; however, the tailgate still failed to open. The vehicle had not been taken to the dealer to be diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 1,000.