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Service bulletins for the 2020 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.

1990 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

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

Bulletins, newest first
HT-03.03.20202020-09-19. Service bulletin. ELECTRICAL SYSTEM. Hypertech Inline Speedometer Calibrator Module Installation Instructions
PIT5751B2020-09-14. Service bulletin. ELECTRICAL SYSTEM:WIRING; ENGINE. This Preliminary information communicates and issue with the SES MIL on setting DTC's P0201/P0202/P0203/P0204/P0205/P0206/P0216 and instructing dealership to inspect the engine wiring harness for damage.
PIP5647B2020-09-14. Service bulletin. ELECTRICAL SYSTEM; ENGINE; FUEL SYSTEM, GASOLINE. This Preliminary information communicates A vehicle may have a concern of running poor and stalling. No trouble codes may be set referencing this condition. Fuel trims around -20% may be observed on both banks. Engine oil level will be found over full and have a fuel odor. It will be found that the Engine oil is diluted with fuel. Small gas engines (SGE) May only have the engine oil level over full and have a fuel odor. It will be found that the Engine oil is diluted with fuel. This concern is caused by marshalling the vehicle around the lot before it is sold and/or short driver cycles.
PIT5735C2020-09-14. Service bulletin. EQUIPMENT; FORWARD COLLISION AVOIDANCE: DYNAMIC BRAKE SUPPORT/BRAKE ASSIST; ELECTRICAL SYSTEM. This Preliminary information communicates an issue with a SES MIL and the Brake System Control Module setting false DTC's during shut down. GM Engineering released updated cals for the BSCM to repair the issue.
PIE0566A2020-09-08. Service bulletin. ELECTRICAL SYSTEM. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the Malfunction Indicator Lamp (MIL) Illuminated and/or functional failures of the Airflow Shutter.
PIE0562A2020-09-08. Service bulletin. ELECTRICAL SYSTEM. This engineering information (EI) revision ends the need for information from the field regarding Check Trailer Message on Drivers Information Center (DIC) and/or F74, F82 Fuses Blown.
070842006O2020-09-08. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ELECTRICAL SYSTEM. This informational 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.
PIP57452020-08-10. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates to technicians a possible cause and correction for a P026A
PIP5733A2020-08-10. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates Possible Crank no start or extended crank with DTC p12A6 set current or history. Under Investigation
PIT5742A2020-08-10. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates an issue with the engine wiring harness shorting on the ecm mounting bracket and provides repair instructions.
PIT5737B2020-08-10. Service bulletin. EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; ELECTRICAL SYSTEM. This Preliminary information communicates an XM service concern of no audio at startup until a channel change and directs to contact XM for direct support.
PIT5751A2020-08-10. Service bulletin. ENGINE; ELECTRICAL SYSTEM:WIRING. This Preliminary information communicates and issue with the SES MIL on setting DTC's P0201/P0202/P0203/P0204/P0205/P0206/P0216 and instructing dealership to inspect the engine wiring harness for damage.
PIT57562020-08-10. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates an issue with the underhood electrical center bolts being loose which can cause any of the following symptoms: - No crank - No start - Starter grinds or reengages after engine running - Headlights flicker or flash - SES MIL - IPC gauges sweep/fluctuate and various IPC warning lights or messages - High or low system voltage Some of these concerns may be notices with powertrain movement, like when either accelerating or braking.
PIT57552020-08-10. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates an issue with the Electronic Brake Control Module incorrectly mapping DTC U0126 as a U0131 and directs the dealership to follow the diagnostics for the U0126.
PIT5509G2020-08-10. 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.
PIT57522020-08-10. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. This Preliminary information communicates multiple vehicle issues caused by an aftermarket device and it gives dealership information where to inspect for this device.
PIT57512020-08-10. Service bulletin. EQUIPMENT; ENGINE; ELECTRICAL SYSTEM:WIRING. This Preliminary information communicates and issue with the SES MIL on setting DTC's P0201/P0202/P0203/P0204/P0205/P0206/P0216 and instructing dealership to inspect the engine wiring harness for damage.
PIT57502020-08-10. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY; ELECTRICAL SYSTEM:WIRING. This Preliminary information communicates an issue with the battery goes dead and provides diagnostics tips on inspecting the LIN bus.
PIT57472020-08-10. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT:RECREATIONAL VEHICLE/TRAILER. This Preliminary information communicates to dealership how to test properly trailer light option on the truck and also provide additional information on trailer issues.
PIT57452020-08-10. Service bulletin. ELECTRICAL SYSTEM; SEATS. This Preliminary information communicates and issue with the memory seat module waking up the low speed GM lan bus and causing a battery draw.
PIP5728B2020-08-10. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. This Preliminary information communicates to the dealer an issue where a module configuration function is missing from GDS2 scan tool. Dealer is instructed to manually build the vehicle in GDS2 and perform the function until software update is available.
20NA1322020-08-10. Service bulletin. ELECTRICAL SYSTEM. This warranty administration bulletin provides policy information on the requirements for battery testing and warranty replacements.
20NA1052020-08-10. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM:ADAS:DRIVER MONITORING:CAMERA/SENSOR; STRUCTURE:BODY:TAILGATE. This technical bulletin provides repair information to correct a customer concern of 360 Camera Views go Blank with Tailgate Removed.
20NA1002020-08-10. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This informational bulletin provides information for dealers/technicians on Engine Control Module Calibration for T1 L3B Engine with DTC P26BB Set.
20NA0122020-08-10. Service bulletin. EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; ELECTRICAL SYSTEM:SOFTWARE. This Technical bulletin provides service procedure information for dealers/technicians on Radio Software Version V135116 Over-the-Air Update.

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