2021 GMC Yukon electrical problems

Filed Oct 24, 2026 · Electrical · GA

About 1 month ago while driving down the highway, my vehicle dash and screen went completely back for a few seconds and came back on. As if it shorted out

Filed Sep 11, 2026 · Electrical · FL

Water is entering the passenger cabin through failed front sunroof drain tubes on both the left and right sides. The drains discharge inside the A pillars rather than to the exterior, pooling in the driver's side floorboard. An authorized GMC dealer diagnosed the cause in writing on August 12, 2026 as rubber grommet shrinkage and hardened internal buildup preventing water from flowing through, on both the left and right sides simultaneously. The identical bilateral failure mode indicates a component or assembly defect rather than debris blockage. Water is accumulating in the driver's footwell in proximity to cabin electrical components and the fuse block area, creating a risk of electrical shorting, connector corrosion, and circuit failure. Mold has developed in the front carpet and padding on the driver's side, and water intrusion staining is present on the passenger side. The dealer has quoted $2,727.16 to replace the drain tubes and the mold-damaged carpet and padding. The vehicle entered service on February 5, 2025 and has 45,211 miles. GM has issued service bulletin 20-NA-219 addressing sunroof drain hoses on 2021 Yukon, Yukon XL, Tahoe, Suburban, and Escalade models.

Filed Aug 31, 2026 · Electrical · SC

While driving the vehicle on the interstate, the vehicle shifted to neutral without warning. Our daughter was able to fortunately coast to the side of the interstate without incident. The vehicle was shut off and attempted to turn back on without success, so vehicle was towed to Lugoff Chevy dealership where repairs are always performed. The dealership stated the problem was related to fuse block melted and shorted. The problem was fixed; however, I am not convinced that this shouldn't be something requiring a recall and needs further investigation. There was no warning lamps, messages, or symptoms prior to the failure.

Filed Aug 26, 2026 · Electrical, Fuel system · MN

1. What component or system failed or malfunctioned. The Fuel Pump Module failed unexpectedly while the vehicle was being driven. Failure caused the engine to stall, resulting in a complete loss of power and mobility. Unsure if part is available for inspection. 2021 GMC Yukon have a recall N252516900, but our VIN is not included in this. Can our VIN be added to this recall please? 2. How was your safety or the safety of others put at risk? The vehicle abruptly stalled while being driven through a parking lot, causing a complete loss of power and leaving the vehicle disabled in an active traffic area. Because the vehicle could not be shifted out of PARK, it became an obstruction, creating a hazard for other drivers navigating the parking lot and increasing the risk of a collision. 3. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. After the vehicle was towed to a local mechanic on a flatbed truck, the dealer diagnosed and confirmed that the Fuel Pump Module had failed, which caused the vehicle to stall and lose power. 4. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives, or others? The vehicle was inspected by a local repair shot, which diagnosed the failed Fuel Pump Module. The vehicle was also evaluated during the towing process. To my knowledge, the manufacturer, police, or insurance representatives have not separately inspected the vehicle or component. 5. Were there any warning lamps, messages, or other symptoms of the problem prior to the failure, and when did they first appear? Prior to the failure, there were no significant symptoms indicating an imminent fuel system failure. When the incident occurred, the vehicle abruptly stalled, lost all power, and displayed a message indicating that the vehicle was "not in a condition to shift," preventing it from being shifted out of PARK. This message first appeared immediately following event.

Filed Aug 18, 2026 · Brakes, Electrical · TX

As I was driving, the vehicle's air conditioning suddenly began blowing warm/hot air. Moments later, the check engine light and all electronic service stability lights illuminated on the dashboard. Simultaneously, the vehicle suffered a complete loss of electronic brake assist, resulting in an extremely hard brake pedal and a severe reduction in braking power. The vehicle also displayed a "No Drive Mode Available" message. Third-party diagnostic scanning revealed network power codes U3018, U3505, P00FF, and P0700, indicating a total loss of power to the Body Control Module (BCM). This is the second life-threatening incident with this vehicle I have experienced following a previous highway engine stall due to engine recall. The vehicle was towed to a GM dealership for diagnostic and emergency electrical repairs.

Filed Jun 23, 2026 · Airbags, Electrical · NH

The driver's seat inboard airbag assembly and internal structural wiring harness failed due to a direct short circuit, completely deactivating the vehicle's supplemental restraint system. General Motors has a known engineering bulletin for this issue (#23-NA-085), noting that sharp internal seat frame components slice the airbag wiring harness. Rather than permanently fixing this structural design flaw while under warranty, dealership technicians repeatedly executed temporary, non-compliant field patches, including plastic zip-ties and Velcro tape inside the cushion. These temporary patches continuously failed, leaving the airbags disabled. Furthermore, the vehicle was sold under "Certified Pre-Owned" designation with an active, uncompleted 2020 manufacturer Customer Satisfaction Program Campaign (#N202310850-02) for this exact airbag circuit defect. Component failed & available for inspection: The driver's seat inboard airbag assembly and internal structural wiring harness failed due to a direct short circuit. The components are available for inspection inside the vehicle at the servicing dealership. Safety risk: Safety was put at extreme risk because active Diagnostic Trouble Code B14DC completely deactivates the airbags. This means the airbags may fail to deploy in a collision, leaving the driver completely unprotected in an accident. Confirmed by dealer: The problem has been explicitly reproduced and confirmed by an authorized franchise dealership across seven separate service visits spanning from August 2025 to June 2026. Inspected by manufacturer/others: The components have been physically inspected multiple times by authorized franchise dealership technicians acting on behalf of the manufacturer. Warning lamps & symptoms: The vehicle displays "Service Safety Restraint System" warning message on the dashboard. The warning lamp first appeared on August 26, 2025, at 78,472 miles while the vehicle was strictly within its CPO warranty

Filed Jun 3, 2026 · Electrical, Engine · 42,000 miles · NY

The contact owns a 2021 GMC Yukon. The contact stated that while driving approximately driving 45 MPH and turning onto an exit the vehicle suddenly reduce speed and lost power and the message "Press Start" had displayed. The contact stopped the vehicle and eventually restarted the engine and the vehicle operated as normal. The next day the vehicle was driven to the local dealer who was unable to duplicate the problem and determine the cause of the failure. The manufacturer was not yet contact regarding the failure. The failure mileage was 42,000.

Filed May 16, 2026 · Electrical, Transmission · AK

transmission has been replaced, still having same problems. Actuator was fixed within the transfer case. still shaking. was driven by dealer and told to check again after changing into summer tires. changed into summer tires and still having issues if not worse. separately; the power running boards have never worked - been told its wiring issue. wiring issue is a concern for fire safety.

Filed Dec 27, 2025 · Electrical, Engine · TX

The vehicle shifted into Neutral while driving, locked out gear selection, triggered a transmission warning, and now will not restart.

Filed Dec 22, 2025 · Airbags, Driver assistance · NC · crash · 1 injury

Vehicle: 2021 GMC Denali Mileage: ~48,000 miles Purchase Price: $62,000 Issue: Airbags & crash sensors failed to deploy Complaint Text: I am filing a safety complaint regarding my 2021 GMC Denali. I was involved in a rear-end collision at approximately 45 mph, where I struck another vehicle straight on from behind. The impact was severe enough to total my vehicle, yet no airbags deployed, and no forward collision warning or crash sensor systems activated. This is especially concerning because this vehicle was previously involved in a front-end collision (not my fault) and underwent extensive repairs. I was assured all systems were repaired and functioning properly. Additionally, my vehicle had completed recall work related to safety systems prior to this crash. This is the second front-end crash involving this vehicle where airbags failed to deploy. Given the speed and severity of the impact, airbags should have deployed. The failure of these systems placed my life at serious risk. The vehicle has since been totaled and taken by insurance, but I am requesting that this failure be formally investigated as a potential safety defect in the airbag and sensor systems. I am extremely concerned that the vehicle’s safety systems were either defective or not properly restored following repairs and recalls.