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Service bulletins for the 2021 Chevrolet Express

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.

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

By type

By component

By trouble code

By topic

Bulletins, newest first
21NA1152021-08-09. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM). This informational bulletin provides information for dealers/technicians on Available ECM Calibration to Activate High Idle Mode for Fleet Vehicles
100089006H2021-08-09. Service bulletin. EQUIPMENT. This service bulletin provides information for dealers on how to submit a product information report (PIR) (Canada Only).
070089037Q2021-08-09. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs.
070089037P2021-08-09. Service bulletin. EQUIPMENT. This warranty administration bulletin provides policy information for GM courtesy transportation and roadside assistance programs.
PIT5039D2021-07-19. Service bulletin. STRUCTURE:BODY:BUMPERS. This Preliminary Information communication provides information to the technician about vehicles that the customer or up-fitter may have removed the rear bumper, install a different rear bumper, or add a different box/flat bed/cube box/hitch, etc. to the rear of the truck, which affects the rear park assist operation. Technician can disable the rear park assist for this concern.
21NA1242021-07-19. Service bulletin. FUEL SYSTEM, GASOLINE:STORAGE:EVAPORATIVE EMISSIONS:CANISTER. This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set.
21NA1092021-07-19. Service bulletin. ENGINE. This service bulletin provides diagnostic information for a customer concern of engine vibration.
20NA1592021-07-19. Service bulletin. EQUIPMENT. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only).
19NA0442021-07-19. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy.
18NA3062021-07-19. Service bulletin. EQUIPMENT. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA).
21NA1242021-07-06. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set.
21NA1092021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides diagnostic information for a customer concern of engine vibration.
20NA1592021-07-06. Service bulletin. TIRES. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only).
19NA0442021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy.
18NA3062021-07-06. Service bulletin. EQUIPMENT. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA).
N2123306602021-06-14. Service bulletin. SERVICE BRAKES, HYDRAULIC. Service Update Bulletin. Certain vehicles may have an erratic signal coming from the engine manifold absolute pressure (MAP) sensor. Customers may notice the service engine soon (SES) lamp illuminate or was illuminated and turned off. DTC?s P0106 and P0108 may also be present as active or stored in history. Dealers will replace the MAP sensor.
PIT5125F2021-06-14. Service bulletin. EXTERIOR LIGHTING; ELECTRICAL SYSTEM. This Preliminary Information communication provides information to the technician about vehicles proper operation of the stop and/or turn signals. For vehicles without Regular Production Option Code V4D circuit 618 is for the left stop and turn signal and circuit 619 dark green is for the right stop and turn signal. For vehicles with Regular Production Option Code V4D circuit 618 yellow is for the left turn signal only. Circuit 619 dark green is for the right turn signal only and circuit 1320 light blue is for the stop lamps only.
PIT5058G2021-06-14. Service bulletin. SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP:ABS WARNING LIGHT; SERVICE BRAKES, HYDRAULIC. This Preliminary Information communication provides information to the technician about the operation and diagnostics of the Regular Production Option Code UJ1 brake warning pressure warning system. The technician can test the operation of the brake warning system. If the warning system does not function correctly, technician will need to inspect circuit 33 for a short to ground between X141 and the Instrument Panel Cluster terminal 14. Then inspect check circuit 33 for an open between X141 and the Instrument Panel Cluster terminal 14. Also technician should check male side of X141 circuit 33 with an ohm meter to ground and should be close to 0 ohms with engine off and key on. Start engine and circuit should go (OL) indicating that the flow switch opened. Then, turn the steering to the stop in pressure relief and verify that the circuit stays (OL) to check the operation of the pressure switch.
070089036J2021-06-07. Service bulletin. EQUIPMENT. This service bulletin provides information on Enhancing Field Product Reports with Digital Pictures.
050308002I2021-06-07. Service bulletin. SUSPENSION. This service bulletin provides information to dealership personnel on diagnosis and replacement of shock absorber and strut due to fluid leak.
020089002T2021-06-07. Service bulletin. EQUIPMENT. This service bulletin provides information for dealers/technicians on When and How to Submit a Field Product Report (FPR) (U.S. Dealers Only).
000601026N2021-06-07. Service bulletin. ENGINE. This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
5113302021-06-02. Service bulletin. ELECTRICAL SYSTEM. General Motors has decided that a defect, which relates to motor vehicle safety exists in certain 2021 model year Chevrolet Express and GMC Savanna vehicles equipped with 6.6L gas engines. In certain circumstances, anti-rotation tabs on the positive battery cable terminals may come into contact with a fuse block assembly attachment post, causing a short circuit. Clearance between the positive battery cable anti-rotation tab and the fuse attachment posts is small enough to allow contact in certain situations.
21NA1062021-05-24. Service bulletin. POWER TRAIN. This informational bulletin advises the technician to verify the TCM is asleep before trying to repair the transmission in order for all the codes to be re-set.
21NA1032021-05-24. Service bulletin. EQUIPMENT. This service bulletin provides information regarding Witness Marks from Panel Adjustments Made During Manufacturing and that it is considered a normal condition.

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