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
19NA2282020-08-10. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ELECTRICAL SYSTEM. This technical provides a procedure to locate, disconnect and re-connect the TCM electrical connector if found the cause of the customers concerns.
N202294740 012020-07-20. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; STEERING. Service Update - Certain vehicles may require individual software updates to multiple modules to address various minor issues such as steering feel and data communication. Dealers are to reprogram multiple modules.
N1922878402020-06-29. Service bulletin. ELECTRICAL SYSTEM:WIRING; ENGINE. Service Update - Certain vehicles equipped with a 2.7L turbo engine (RPO L3B), may have a condition where the engine wiring harness may have been wrapped and/or routed incorrectly, creating the potential for wear-through in several locations. If this occurred it could allow the engine harness to short to ground and/or be severed, which may lead to a check engine light, reduced engine power, no start condition or in rare cases a stall. Dealers are to inspect harness for correct tape wrapping and install engine harness sleeves.
N1922724002020-06-29. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION; WHEELS. Customer Satisfaction Program - Certain 2019-2020 model year Chevrolet Silverado and GMC Sierra vehicles, equipped with an 8-Speed Automatic Transmission, may have a condition where the rear wheels will lock up at low speeds. An intermittent short circuit is being caused by wire bonds moving under high current and thermal load, making contact with adjacent wire(s) in the transmission control module (TCM). Dealers will replace the TCM.
PIE0568B2020-06-22. 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 Shift to Park Message on Drivers Information Center (DIC) (ONLY On Push Button Ignition), Unable to Remove Key from Ignition Cylinder and/or Difficult to Shift Out of Park.
PIE0568A2020-06-22. 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 Shift to Park Message on Drivers Information Center (DIC) (ONLY On Push Button Ignition), Unable to Remove Key from Ignition Cylinder and/or Difficult to Shift Out of Park.
PIE05682020-06-22. Service bulletin. ELECTRICAL SYSTEM. This engineering information (EI) is requesting information from technicians to perform the checklist provided and contact the engineer listed in regards to Shift to Park Message on Drivers Information Center (DIC) (ONLY On Push Button Ignition), Unable to Remove Key from Ignition Cylinder and/or Difficult to Shift Out of Park.
PIE05672020-06-22. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to SD Code messages displayed on the Radio Screen and/or Instrument Cluster - Navigation System Malfunction.
PIE05662020-06-22. 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.
070849020Q2020-06-22. Service bulletin. ELECTRICAL SYSTEM. This informational bulletin provides information for the IPC odometer programming method quick reference guide.
060089029T2020-06-22. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; EQUIPMENT. This informational bulletin includes information on Interior Cleaning - Instrument Panel (IP), Hard or Plastic Surfaces, Seats, Carpet, Leather, Vinyl, Fabric Cleaner, Stain Remover, Restorer - Product Availability.
060089029S2020-06-22. Service bulletin. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; EQUIPMENT. This informational bulletin includes information on Interior Cleaning - Instrument Panel (IP), Hard or Plastic Surfaces, Seats, Carpet, Leather, Vinyl, Fabric Cleaner, Stain Remover, Restorer - Product Availability.
20NA0962020-06-22. Service bulletin. ENGINE; ELECTRICAL SYSTEM:SOFTWARE. This informational bulletin provides information for dealers/technicians on Glow Plug Control Module Update.
20NA0902020-06-22. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM. This informational bulletin provides a way for the technician to identify if the ECM has been modified.
19NA2692020-06-22. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM:SOFTWARE. This Technical bulletin provides a service procedure for dealers/technicians on installation of Radio Software Version U148 Over-the-Air Update.
PIP5728A2020-06-15. Service bulletin. ELECTRICAL SYSTEM. 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.
PIT5735B2020-06-15. Service bulletin. 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.
PIP57282020-06-15. Service bulletin. ELECTRICAL SYSTEM. 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 buid the vehicle in GDS2 and perform the function until software update is available.
PIP57292020-06-15. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates Some customers may comment that the SES lamp is illuminated or was Illuminated and turned off. During inspection Technician may notice DTC P1682 (Ignition 1 Switch Circuit 2) active or stored in history. DTC?s P0101, P0689. P16A7 or P16BC may also be active or stored in history. Additionally, vehicle may have been into the dealer on a prior service visit and had the MAF sensor replaced for DTC P0101. This condition may be caused by a faulty ignition relay or underhood fuse block terminal concern.
PIP5429A2020-06-15. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. This Preliminary Information communication advises the technician that the customer may experience a 2-3 slip or flare after the vehicle has been sitting for a period of time. Technician can update the Transmission Control Module if working on a model year 2007. On all other model years dealer should communicate to the customer this condition is a normal operating characteristic of their vehicle.
PIP5700C2020-06-15. Service bulletin. ELECTRICAL SYSTEM. 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.
20NA0872020-05-26. Service bulletin. EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; ELECTRICAL SYSTEM. This technical bulletin provides repair information to correct a customer concern of Blank Radio Display or No Audio.
20NA0832020-05-26. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This technical bulletin provides a procedure to check the oil level for correct reading and oil pressure switch is in working order.
20NA0822020-05-26. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This informational bulletin explains why more DEF is being used in diesel engines due to new emission standards.
20NA0732020-05-26. Service bulletin. SERVICE BRAKES; ELECTRICAL SYSTEM. This technical bulletin provides repair information to correct a customer concern of Loss of Brake Assist, Various Messages Displayed in DIC, Brake Pedal Travel and Apply May Feel Different, DTC C0024 Set.

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