2020 GMC Sierra Denali Technical Service Bulletins

359 technical service bulletins (TSBs) are on record for the 2020 GMC Sierra Denali. TSBs are notes manufacturers send to dealers about repair procedures for issues seen in the field. They are not recalls and do not by themselves mean a vehicle has a fault.

• 11014230Jan 31, 2025Wheels, Electrical system, Engine, Visibility (wipers, defrost, mirrors), Brakes. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
• 11014171Jan 31, 2025Body and structure, Vehicle speed control. This service bulletin provides information on proper use of floor mats.
• 11014238Jan 30, 2025Body and structure, Other or unknown. This warranty administration service bulletin provides information about GM Accessories - Dealer-Installed, Repaired or Replaced During Warranty Coverage Period.
• 11014233Jan 30, 2025Engine. This service bulletin provides service information to technicians on guidelines to replace Oil Cooler, Oil Cooler Lines and Oil Tank if the engine was replaced where large amounts of debris has flowed throughout the oiling system.
• 11014239Jan 29, 2025Electrical system, Other or unknown. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
• 11014222Jan 28, 2025Electrical system, Other or unknown. This service bulletin provides information to inform dealership personnel about Law Enforcement and Government vehicles that request to disable or enable content.
• 11014170Jan 27, 2025Exterior lighting. This service bulletin provides information on Exterior Lamp Condensation and Water Leak Information and Replacement Guidelines.
• 11013242Jan 17, 2025Brakes, Electrical system. This informational bulletin advises the technician to check for faults that may be caused by the trailer otherwise found by a possible faulty trailer connector.
• 11013069Jan 9, 2025Transmission and drivetrain, Electrical system, Engine. This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
• 11012929Jan 7, 2025Electrical system. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
• 11012930Jan 4, 2025Other or unknown. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs.
• 11012908Dec 21, 2024Other or unknown. This service bulletin provides information for customers/dealers/technicians on Normal Camera Display Operation - Flashing Diamond - Spot - or UFO like image on Camera Display.
• 11012907Dec 18, 2024Engine. This service bulletin explains how to measure for oil consumption and possible reasons for loss of oil.
• 11012690Dec 14, 2024Other or unknown. This warranty administration bulletin provide policy information for variable diagnostic time allowances on select labor operations (U.S. Only).
• 11012189Dec 6, 2024Electrical system. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
• 11011805Dec 6, 2024Other or unknown, Electrical system. This Preliminary information communicates a GM part number for reflective high temperature heat or insulating tape when repairing wiring harnesses.
• 11011687Dec 4, 2024Other or unknown, Back-over prevention (rear camera). This Preliminary information communication provides information to the technician on installing Regular Production Option Code UVC Rearview Camera. Technician will need to reference the latest version of General Motors Up-fitter Integration Bulletin 152. The information can be found at http://www.gmupfitter.com/ under the "Technical Bulletin" Tab and then "Show all bulletins."
• 11011119Dec 4, 2024Other or unknown. This Preliminary information communicates to dealers GM is working on a solution for outdated Apps
• 11011989Nov 27, 2024Transmission and drivetrain. This service bulletin provides information on the harmful effects of ethylene glycol in transmission fluid.
• 11011996Nov 25, 2024Electrical system, Other or unknown. This service bulletin provides diagnostic/repair information to correct a customer concern of Cellphone not Charging or USB Receptacle Inoperative.
• 11011900Nov 22, 2024Engine. This diagnostic tip bulletin provides additional information on how to diagnose a possible valve, lifter or camshaft issue.
• 11011709Nov 5, 2024Brakes, Body and structure, Wheels, Other or unknown, Engine. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
• 11011205Oct 28, 2024Steering, Transmission and drivetrain, Engine. This informational bulletin explains Unscheduled Supplemental Services and the importance of GM Simplified Maintenance Schedules.
• 11010874Oct 15, 2024Fuel system. This bulletin provides information on how to look for and test for DEF or water in the fuel system and what the specs should be.
• 11010576Oct 11, 2024Other or unknown. This service bulletin provides information on All hazmat parts being returned to the Warranty Parts Center (WPC) must be shipped using Central Transport. Hazardous materials should never be sent by air transportation to the WPC.
• 11010545Oct 9, 2024Other or unknown. This service bulletin provides information on key code security rules and information on GM keycode look-up applications (U.S).
• 11010544Oct 7, 2024Engine. This service bulletin explains how to measure for oil consumption and possible reasons for loss of oil.
• 11010493Oct 5, 2024Body and structure, Other or unknown. This warranty administration service bulletin provides information about GM Accessories - Dealer-Installed, Repaired or Replaced During Warranty Coverage Period.
• 11010490Oct 5, 2024Engine. This service bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
• 11010488Oct 3, 2024Other or unknown. This Warranty Administration bulletin provides information on the Global Warranty Management (GWM) Warranty Parts Center (WPC) Parts Return Program.
• 11010421Oct 3, 2024Electrical system. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
• 11010495Oct 2, 2024Other or unknown. This bulletin provides information on Warranty Administration – Required Operating Procedures - 8 Points (U.S. Only).
• 11010491Oct 2, 2024Other or unknown. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs.
• 11009532Sep 27, 2024Engine. This service bulletin provides information for maintenance cleaning of the fuel injectors and gasoline detergent additive.
• 11009531Sep 27, 2024Engine. This service bulletin provides information for maintenance cleaning of the fuel injectors and gasoline detergent additive.
• 11009764Sep 21, 2024Body and structure, Other or unknown. This service bulletin provides information on Concerns or Questions Regarding Installation of Dealer Installed Accessories.
• 11009760Sep 21, 2024Electrical system. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
• 11009756Sep 17, 2024Engine, Transmission and drivetrain. This bulletin provides information on Policies Applicable to All U.S. Dealers for Engine and Transmission Assembly Replacement Under Warranty, Policy or Customer Enthusiasm and information on Submission of Warranty Transaction in Global Warranty Management.
• 11009088Sep 16, 2024Transmission and drivetrain. This service bulletin provides information on some vehicles that may rock or move slightly forward or rearward while in Park at start up after cold soak. This condition may be accompanied by a clunk noise. This is a slight movement that is more often seen visually, rather than felt, when viewed from the outside and using the auto-start feature, if equipped.
• 11009039Sep 14, 2024Other or unknown. This warranty administration bulletin provides policy information, proper labor operation selection and causal part identification for warranty transactions (U.S. Only).
• 11009037Sep 10, 2024Other or unknown. This service bulletin provides information on Enhancing Field Product Reports with Digital Pictures.
• 11008956Sep 9, 2024Other or unknown. This service bulletin provides information for dealers/technicians on When and How to Submit a Field Product Report (FPR) (U.S. and Canada Dealers Only).
• 11007208Sep 6, 2024Other or unknown. This Preliminary Information communication provides information to the technician about changing the tire and wheel size on vehicles. General Motors will only support a tire calibration for tires that have been sized, tested and designed for the vehicle in question and its applications. Technician should not use the information that is provided by the antilock braking system tire size selection.
• 11008898Aug 27, 2024Other or unknown. The bulletin provides direction on how to locate the Temporary Service Part (TSP) form in GlobalConnect.
• 11006621Aug 26, 2024Electrical system. Vehicle Wide Programming (VWP) is a new process to update software on GM Vehicles. It provides the ability via a single selection within Techline Connect to first identify which modules need updating and then proceed to updating affected modules (with some exceptions). The updating of modules is completed in parallel instead of the technician needing to update one module at a time. This allows a more streamlined…
• 11007936Aug 22, 2024Suspension. This service bulletin provides information to dealership personnel on diagnosis and replacement of shock absorber and strut due to fluid leak.
• 11007935Aug 22, 2024Suspension. This service bulletin provides information to dealership personnel on diagnosis and replacement of shock absorber and strut due to fluid leak.
• 11008906Aug 19, 2024Engine. This service bulletin provides graphics, information and guidelines for engine component wear to assist service personnel as a guideline to perform necessary engine repairs and prevent unnecessary engine replacement.
• 11007721Aug 16, 2024Electrical system, Engine. This service bulletin provides information on AGM batteries that require less frequent charging in storage.
• 11007718Aug 12, 2024Engine. This service bulletin explains how to identify possible DEF system contamination.

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