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Service bulletins for the 2021 GMC Sierra

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

1649 on file from NHTSA, as of 2026-10-19.

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Only bulletins with component: Electrical system are shown. Show all

Bulletins, newest first
21NA2562022-02-14. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); EXTERIOR LIGHTING. This service bulletin provides repair information for dealers/technicians to correct a customer concern of a Malfunction Indicator Lamp Illuminated with DTC P26BB Set.
N212342980-012022-02-04. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:DIESEL; ELECTRICAL SYSTEM:SOFTWARE; FUEL SYSTEM, DIESEL. Service Update. On certain vehicles equipped with a 6.6L diesel engine (RPO L5P), the DEF tank connector may overheat and set the following diagnostic codes (P10D9, P143C and P10F3), which will result in reduced engine speed. Dealers are to reprogram the reductant control module.
N2123429802022-01-27. Service bulletin. ELECTRICAL SYSTEM; FUEL SYSTEM, DIESEL. On certain vehicles equipped with a 6.6L diesel engine (RPO L5P), the DEF tank connector may overheat and set the following diagnostic codes (P10D9, P143C and P10F3), which will result in reduced engine speed. Dealers are to reprogram the reductant control module.
PIT5828A2022-01-24. Service bulletin. ELECTRICAL SYSTEM: INTEGRATED TRAILER BRAKE CONTROL. This Preliminary Information communication provides information to the technician about customers that may request the factory Integrated Trailer Brake Controller Regular Production Option Code (JL1) be installed on their Full-Size Pickup or SUV when the vehicle was not ordered with the option. Dealer should advise the customer it cannot be added to the vehicle.
PIE0663A2022-01-03. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ELECTRICAL SYSTEM. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards the Articulated Running Board (ARB).
070842006Q2022-01-03. Service bulletin. ELECTRICAL SYSTEM:BODY CONTROL MODULE/BCM. This service bulletin provides technicians with information on available BCM calibrations to restore bulb outage detection on vehicles produced by a second stage manufacturer (Upfitter), and/or turn signals flash fast after factory box removed.
21NA2712021-12-27. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM; EQUIPMENT. TGhis bulletin advises the technician of a possible coolant hose that might be kinked causing the customers concern.
21NA2652021-12-27. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT; ELECTRICAL SYSTEM. This technical bulletin provides a procedure to re-route the coolant hose away from the front prop shaft to avoid contact.
21NA2472021-12-27. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM:INSTRUMENT PANEL:FUEL GAUGE:FUEL LEVEL FLOAT/SENSOR/SENDING UNIT. This technical bulletin provides a procedure This technical bulletin provides repair information to correct a customer concern of Unable to Set PIN to Enable Teen Driver Feature.
21NA1492021-12-27. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE; ELECTRICAL SYSTEM:WIRING. This technical bulletin provides repair information to correct a customer concern of Engine Wire Harness Chafing.
20NA1322021-12-20. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY. This warranty administration bulletin provides policy information on the requirements for battery testing and warranty replacements.
PIT5387K2021-09-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary Information communication provides information to the technician how to repair vehicles that Instrument Panel Cluster, Radio, and Heater-Vent-Air Conditioning display blanks out, Bluetooth phone or Pandora connection dropped, the radio station or volume changes when operating the snow plow. Please advise the customer that engineering is aware of this concern and working on this issue.
PIT5662F2021-09-13. Service bulletin. ELECTRICAL SYSTEM:ADAS:PARKING ASSIST:WARNING; PARKING BRAKE. This Preliminary information communicates information to diagnose DTC C056D or C056E.
PIC6438B2021-09-13. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This Preliminary information communicates a condition where the Video Processing Control Module is not able to be programmed to the vehicle. This PI offeres a couple workarounds while Engineering evaluates the concern.
PIC64442021-09-13. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This Preliminary information communicates a possible SIM issue with vehicles in the middle east.
PIT5743A2021-09-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates diagnostic tips when trying to root cause a SES MIL with DTC's B2B0D and B2B0E. Main cause is aftermarket electrical devices spliced into the ignition main fuses.
PIP5806C2021-09-13. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This preliminary information bulletin instructs to technicians to check the trigger wheel for interfering with the timing chain, and adding a shim to the camshaft position sensor.
PIC6438A2021-09-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a condition where the Video Processing Control Module is not able to be programmed to the vehicle. This PI offeres a couple workarounds while Engineering evaluates the concern.
PIC64382021-09-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a condition where the Video Processing Control Module is not able to be programmed to the vehicle. This PI offeres a couple workarounds while Engineering evaluates the concern.
PIT5509H2021-09-13. Service bulletin. AIR BAGS; TRAILER HITCHES; ELECTRICAL SYSTEM. This Preliminary Information communication provides information to the technician on how to diagnose and repair vehicle that may have a "Check Trailer Wiring" or "Service Trailer Brake System? message on the Driver Information Center when a trailer is connected to the vehicle. Diagnostic Trouble Code C1114 set in the Chassis Control Module. Chassis Control Module has to determine the type of trailer brake system that is being used. The Chassis Control Module can be sensitive to a variety of trailer wiring issues. The technician will need to make a trailer tester using Electric Trailer Brake Magnets and 7-way trailer connector to determine if it is a vehicle or trailer issue. If the concern is not duplicated with the tester installed, the vehicle is operating correctly and the focus should be on the trailer wiring or 7 way connector.
PIT5698B2021-09-13. Service bulletin. ELECTRICAL SYSTEM:ADAS:BLINDSPOT:SENSORS. This Preliminary information communicates additional information on how a LIN bus operates and diagnostic tips when working on a LIN bus.
PIT5509H2021-09-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary Information communication provides information to the technician on how to diagnose and repair vehicle that may have a "Check Trailer Wiring" or "Service Trailer Brake System? message on the Driver Information Center when a trailer is connected to the vehicle. Diagnostic Trouble Code C1114 set in the Chassis Control Module. Chassis Control Module has to determine the type of trailer brake system that is being used. The Chassis Control Module can be sensitive to a variety of trailer wiring issues. The technician will need to make a trailer tester using Electric Trailer Brake Magnets and 7-way trailer connector to determine if it is a vehicle or trailer issue. If the concern is not duplicated with the tester installed, the vehicle is operating correctly and the focus should be on the trailer wiring or 7 way connector.
N2123338002021-08-09. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); ELECTRICAL SYSTEM. Emission Recall. General Motors has decided to conduct a voluntary emissions recall involving certain vehicles equipped with a performance air intake system (LPO RVK or 5W7). The Engine Control Module (ECM) may not have been programmed with the calibrations appropriate for the performance air intake system installed on the engine in these vehicles. Dealers will reprogram the ECM.
N2123328202021-08-09. Service bulletin. EQUIPMENT:APPLIANCE:TV/RADIO/SPEAKERS; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; ELECTRICAL SYSTEM:SOFTWARE. Service Update. Certain vehicles may not be able to access Apps. A most notable improvement list this software update may correct is located at the end of this bulletin for conditions or concerns a customer may experience. Dealers will reprogram the radio.
N2123365702021-08-09. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); FUEL SYSTEM, GASOLINE. Service Update. Certain trucks may falsely set fuel injector diagnostic trouble codes P026C and/or P20EE. Dealers will reprogram the engine control module (ECM).

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.