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Service bulletins for the 2021 Chevrolet 4500HD

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.

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

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

Bulletins, newest first
20-NA-0512025-06-25. Service bulletin. ELECTRICAL SYSTEM. This informational bulletin provides information on the Low Cab Forward trucks and the Alpine Radio Exchange Program.
13-08-116-001K2025-04-25. Service bulletin. ELECTRICAL SYSTEM. The intent of this service 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.
15-06-03-001F2025-04-15. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides information to diagnose batteries that have set for a long period of time and/or cold weather climates and testing those batteries.
17-NA-0502025-02-28. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM; ENGINE. This service bulletin explains how a health report is required when doing repairs on MD LCF vehicles.
23-NA-0642025-02-12. Service bulletin. ELECTRICAL SYSTEM; UNKNOWN OR OTHER. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
21-NA-0432025-02-12. Service bulletin. VISIBILITY/WIPER; SERVICE BRAKES; ENGINE; ELECTRICAL SYSTEM; WHEELS. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
20-NA-1322025-01-18. Service bulletin. ELECTRICAL SYSTEM. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
23-NA-0642025-01-03. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
22-NA-2382024-12-19. Service bulletin. UNKNOWN OR OTHER; ELECTRICAL SYSTEM. This service bulletin provides diagnostic/repair information to correct a customer concern of Cellphone not Charging or USB Receptacle Inoperative.
PIT5962B2024-12-12. Service bulletin. ELECTRICAL SYSTEM; UNKNOWN OR OTHER. This Preliminary information communicates a GM part number for reflective high temperature heat or insulating tape when repairing wiring harnesses.
20-NA-1322024-11-09. Service bulletin. ELECTRICAL SYSTEM. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
23-NA-0642024-11-05. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
23-NA-0442024-09-11. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This service bulletin provides information on AGM batteries that require less frequent charging in storage.
General Communication2024-08-26. Service campaign. ELECTRICAL SYSTEM. Vehicle Wide Programming (VWP) is a new process to update software on GM Vehicles. It provides the ability via a single selection within Techline Connect to first identify which modules need updating and then proceed to updating affected modules (with some exceptions). The updating of modules is completed in parallel instead of the technician needing to update one module at a time. This allows a more streamlined approach for dealers and customers.
PIT61732024-08-13. Service bulletin. ELECTRICAL SYSTEM; UNKNOWN OR OTHER. This Preliminary information communicates a diagnostic tip to inform dealership technician on how to reset/learn the BPP sensor in the Powertrain Interface Module (PIM)
12-01-37-001G2024-08-13. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides information to dealership personnel on a new refrigerant (R1234yf) for A/C service.
18-NA-1252024-06-28. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides information for engine oil life monitor operation calculation.
23-NA-0642024-06-10. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
18-NA-1252024-06-08. Service bulletin. ENGINE; ELECTRICAL SYSTEM. This service bulletin provides information for engine oil life monitor operation calculation.
23-NA-0642024-05-16. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
13-08-116-001J2024-05-16. Service bulletin. ELECTRICAL SYSTEM. The intent of this service 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.
23-NA-1252024-05-16. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on Over The Air (OTA) and In Market Enhancement (IME) FAQs.
23-NA-0642024-05-02. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
20-NA-1322024-04-23. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
20-NA-1322024-04-05. Service bulletin. ELECTRICAL SYSTEM; ELECTRICAL SYSTEM:12V/24V/48V BATTERY; ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; EQUIPMENT. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.

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