WenmarOpen by Wenmar Pro

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
20NA0122020-05-26. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This Technical bulletin provides service procedure information for dealers/technicians on Radio Software Version V135116 Over-the-Air Update.
19NA0762020-05-26. Service bulletin. ELECTRICAL SYSTEM. This technical bulletin provides repair information to correct a customer concern of Blue Screen and Service Rear Vision System Message on Radio Display.
PIT57432020-05-11. 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.
PIT5195F2020-05-11. Service bulletin. ELECTRICAL SYSTEM. This Preliminary Information communication provides information to the technician about vehicles that the speedometer needle appears to be inaccurate. Dealer should advise the customer the specification for speedometer needle accuracy is +/- 2 MPH at any given speed when looking straight at the needle.
PIP5647A2020-05-11. Service bulletin. FUEL SYSTEM, GASOLINE; ELECTRICAL SYSTEM. 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.
PIT5735A2020-05-11. Service bulletin. ELECTRICAL SYSTEM; SERVICE BRAKES. 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.
PIE0546A2020-05-04. Service bulletin. ELECTRICAL SYSTEM. This engineering information (EI) is requesting information from the field on conditions of Service Engine Soon (SES) Lamp Illuminated, DTCs B2B0D and/or B2B0E Central Gateway Module Codes Unable to Communicate with HSLAN or LSLAN. Eng is attempting to root cause condition and validate a field fix.
20NA0402020-04-27. Service bulletin. LATCHES/LOCKS/LINKAGES:TAILGATE:LATCH; ELECTRICAL SYSTEM. This technical bulletin provides repair information to correct a customer concern of the pickup box power endgate may not open on initial press, or may not open at all.
20NA0122020-04-27. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ELECTRICAL SYSTEM:SOFTWARE. This Technical bulletin provides service procedure information for dealers/technicians on Radio Software Version V135116 Over-the-Air Update.
20NA0672020-04-27. Service bulletin. ELECTRICAL SYSTEM. This informational bulletin provides information for dealers/technicians on Accessory Rear Seat Infotainment (RSI) Shuts Off, Coinciding with Closing of Door or Liftgate.
20NA0662020-04-27. Service bulletin. ELECTRICAL SYSTEM. This technical bulletin provides a procedure to program the glow plug control module if found the cause of the customers concerns.
PIT5677C2020-04-13. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This Preliminary information communicates the following issues and directs dealership to inspect the engine harness for shorting. Some customers may comment on any of the following concerns: - SES MIL - No Start - No Crank - Engine runs rough - Reduced engine power - Erratic speedo - Blown Fuse(s): F46UA, F47UA, F51UA, F78UA, F85UA, F86UA, F87UA, and/or F90UA When checking for DTC's any combination may be found: C15AA P001A P2B00 P2B01 P2B03 P2B96 P001B P003D P0107 P018C P01E5 P01E6 P01E7 P0237 P0340 P0341 P0355 P0365 P037C P03F0 P0521 P0522 P0532 P0616 P077C P07BF P1101 P112F P146D P159F p16A0 p16A2 P171B P2122 P26E5 P2812 P2814 P2B53 P2C05 P2C08 P2C09 P2C0C P2C0D P2C10 P2C12 P2C15 P2C16 P2C19 P305E P3084 P3089 P308E P3093 P3094 P3095 P3098 P30B0 P30B3 P30CF U0073 U0100 U0101 U0140 U0644 U0672
PIT5509F2020-04-13. Service bulletin. ELECTRICAL SYSTEM; SERVICE BRAKES, ELECTRIC. 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.
PIP57172020-04-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates that there is software update available for the TCCM to correct a software anomaly.
PIP57162020-04-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates that there is software update available for the TCCM to correct a software anomaly.
PIP5675B2020-04-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates to the dealer that a customer may comment that the MIL light is illuminated. The technician may find P1098 and/or P26BB set current or history. That this may be caused by a software anomaly, and that GM is currently looking into the issue. It provides testing and related direction based on the results.
PIT57352020-04-13. Service bulletin. ELECTRICAL SYSTEM; SERVICE BRAKES. 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 is working on updated cals for the BSCM.
PIP5700B2020-04-13. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. This Preliminary information communicates to the dealer technician that the part numbers for the internal wiring harnesses for the 8 speed RWD transmissions are not listed in the Electronic Parts Catalog. Technicians are to refer to the information provided in this document to obtain the internal wiring harness part numbers by application.
PIP57112020-04-13. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This Preliminary information communicates to the dealer technicians a warm engine knock noise has no short or long term effects on the engine. Do not attempt repairs for this noise.
PIE05542020-04-06. Service bulletin. ELECTRICAL SYSTEM. This engineering information (EI) is requesting information from the field to perform the check list provided and contact the engineer in regards to Instrument Panel Cluster (IPC) Gages at Zero, Multiple Warning Lights On, No Chimes and/or Turn Single Audio.
DOR-D8C4T-032020-03-30. Service bulletin. ELECTRICAL SYSTEM; VISIBILITY:POWER WINDOW DEVICES AND CONTROLS. This SKU is a Power Window Regulator and Motor Assembly. The customer communication requested return of unsold inventory to inspect the software. The software may be too sensitive to the position of a locating magnet in the assembly causing the activation of the pinch point threshold prematurely. The window will stay open when it should have closed.
N2022948202020-03-23. Service bulletin. SERVICE BRAKES; ELECTRICAL SYSTEM. Customer Satisfaction Program - The brake system control module software in these vehicles may contain an error. If (i) the vehicle is started remotely using the MyChevrolet, MyGMC, or MyCadillac mobile app or (ii) the driver enters the vehicle and waits five or more minutes before starting the vehicle using the ignition, this software error can, in rare cases, disable the vehicle?s electronic brake assist and illuminate the ESC, ABS and BRAKE telltales. This occurs at startup and the telltales are illuminated before the driver puts the vehicle into gear. Dealers will reprogram the brake system control module.
N192266750-022020-03-23. Service bulletin. FUEL SYSTEM, DIESEL; EQUIPMENT; ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN; ELECTRICAL SYSTEM. Service Update - On vehicles that are equipped with a 6.6L diesel engine, may have one or more of the following conditions exist: 1. The instrument panel cluster may incorrectly display the message ?DEF Low? when a diesel exhaust fluid (DEF) controller internal fault is detected (DTC P20FF), instead of displaying the proper ?Service DEF System? message. 2. The customer may complain of excessive engine fan noise at a low vehicle speed. 3. Under certain conditions, the diagnostic system may set one of the following DTC?s when there is no problem with a component: (P20EE, P226D, P16F3 and P129F). Dealers are to reprogram the engine control module and perform NOx and Catalyst Resets and Regen Enable.
N192282970-012020-03-23. Service bulletin. ELECTRICAL SYSTEM; ENGINE. Service Update - Certain vehicles may have a condition where the check engine or the reduced power mode light may come on during start-up or while driving. Reprogram the engine control module and the reductant control module.
PIT5730A2020-03-09. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates repair information on Service Brake System, Reduced Engine Power, and Speed Limited messages on the DIC. Along with these messages, a SES MIL will be on and the brake pedal may feel hard. When checking for DTC's the Brake System Control Module (BSCM) with have set a P0606 and C0021. Dealers are to reprogram the BSCM with updated calibrations to correct the concern.

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