WenmarOpen by Wenmar Pro

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.

By type

By component

By trouble code

By topic

Bulletins, newest first
PIP5700G2026-01-19. Service bulletin. UNKNOWN OR OTHER. This PI communicates the proper part numbers for transmission connectors and internal harness to prevent confusion when ordering
PIP4902U2026-01-13. Service bulletin. UNKNOWN OR OTHER. This preliminary information advises a dealer on how to email GDS2 session logs into Technical Assistance.
PIT5828E2026-01-13. Service bulletin. UNKNOWN OR OTHER. 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.
PIT6276B2026-01-13. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates an issue with a service keyless entry message caused by aftermarket door handle covers and they should be removed.
N2525342002026-01-06. Service campaign. UNKNOWN OR OTHER. General Motors has decided to conduct a voluntary emissions recall. A Vehicle Emissions Control Information (VECI) label with correct information may not be present. Dealers are to install a new VECI label.
PIT5689M2026-01-04. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates that some customers may comment that after an auto-stop event the engine does not restart and to inspect the engine ground strap. Temporarily on hold while PIE0572 is active. PIE0572 has now ended and reinstating the PI.
PIT5984A2025-12-29. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates a diagnostic tip for an issue where the starter stays engaged after the engine starts. Dealers are to suspect/monitor the crankshaft position sensor.
N25-2505522025-12-24. Over-the-air update. UNKNOWN OR OTHER. Improvements to OnStar functionality. During the update process, your radio may stay on up to 5 minutes after you exit the vehicle. This is expected behavior when an update package is onboard the vehicle. Do not service your vehicle during installation.
25-NA-1562025-12-04. Service bulletin. WHEELS. This service bulletin provides information on Tire Sidewall Irregularities.
PIT6132D2025-12-03. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates an issues with the HVAC making a hum buzz noise when the blower is set to a higher speed. Engineering is working on a new HVAC door seal material to correct the noise.
25-NA-0802025-12-03. Service bulletin. POWER TRAIN. This service bulletin provides a procedure to overhaul the control valve to replace a plate and worn down check ball to correct the customers concern of No Reverse, No Shift Past Third Gear - DTC P2732 Set.
24-NA-2622025-12-03. Service bulletin. POWER TRAIN. This bulletin helps aid the tech in possible 10L100 transmission noise that may be normal or abnormal depending on the concern noted.
07-08-42-006U2025-12-03. Service bulletin. EXTERIOR LIGHTING. 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.
00-06-01-026R2025-12-03. Service bulletin. ENGINE. This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
PIT5214G2025-11-28. Service bulletin. UNKNOWN OR OTHER. This Preliminary Information communication provides information to the technician about vehicles that have had multiple repair attempts that are being performed on customer’s vehicles that exhibit vibration conditions without utilizing the support of General Motors Technical Assistance Center. If valid vibration frequency or Road Force Variation data has been collected and a repair attempt does not correct the customer complaint, contact General Motors Technical Assistance Center for further support. For any vehicles that remains unrepaired after being at the dealer for three days or more and a related bulletin or PI is not found, contact General Motors Technical Assistance Center for further support.
25-NA-3392025-11-12. Service bulletin. ENGINE. Under Field Actions N252494000, N252494001, the service procedure includes performing a PICO test on vehicle engines within the identified suspect VIN population. If the engine passes the PICO test, the engine oil will be changed from 0W20 to Mobil 1 Supercar 0W40 dexosR. From that point forward, the engine must use 0W40 dexosR oil products for all future oil change services.
PIP5865J2025-11-10. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates the possibility of DTC P30BF failing on low mile vehicles due to the possibility of the cylinder 1/2 sliding barrel binding on intake camshaft.
PIP5700F2025-11-03. Service bulletin. UNKNOWN OR OTHER. This PI communicates the proper part numbers for transmission connectors and internal harness to prevent confusion when ordering
PIT6132C2025-11-02. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates an issues with the HVAC making a hum buzz noise when the blower is set to a higher speed. Engineering is working on a new HVAC door seal material to correct the noise.
PIC6591C2025-11-02. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to dealer to contact TAC for a specific display issue.
23-NA-1702025-10-25. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This bulletin advises the tech to inspect deeper into what may be to main cause of an engine failure.
23-NA-1532025-10-25. Service bulletin. ENGINE. The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
PIT6425B2025-10-24. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's
PIC6551A2025-10-24. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to dealer to perform a MEC reset for wireless projection issues
PIT6425A2025-10-24. Service bulletin. UNKNOWN OR OTHER. This Preliminary information communicates to the field on how to diagnosis a GPS issue with the Telematic module with no DTC's

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