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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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By component

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

Bulletins, newest first
PIT57932020-12-14. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:ELECTRICAL:NAVIGATIONAL SYSTEM(GLOBAL POSITIONING SYSTEM). This Preliminary information communicates that engineering is Work on a Software fix for some radio apps not Opening, Connected Navigation (live traffic, etc.) is not functioning (base navigation functions correctly)
PIE05942020-12-07. Service bulletin. ELECTRICAL SYSTEM. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards an intermittent no start.
1308116001F2020-12-07. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION. The intent of this technical bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.
20NA1962020-11-30. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides information and a service procedure for dealers/technicians on OnStar Over the Air Update for TTY / TDD Operation and Continuous Improvement Changes.
20NA0432020-11-30. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This informational bulletin advises the technician to not replace the TMAP sensor, clean it using air or harsh chemicals but allow time for the sensor to thaw.
PIP5711A2020-11-16. 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.
PIT5387H2020-11-16. Service bulletin. EQUIPMENT; 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.
20NA1572020-10-26. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This bulletin provides information on the Transport Mode On Message Being Displayed in the Driver Information Center (DIC) and/or Battery Light is Flashing and the procedures to turn the Transport Mode message ON and OFF.
20NA1572020-09-28. Service bulletin. ELECTRICAL SYSTEM. This bulletin provides information on the Transport Mode On Message Being Displayed in the Driver Information Center (DIC) and/or Battery Light is Flashing and the procedures to turn the Transport Mode message ON and OFF.
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
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.

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