GM To Fix Erroneous Air Fuel Enrichment On Chevy Camaro, Malibu, Trailblazer And Buick Encore GX

General Motors has issued a service update to address a problem with the engine air-fuel mixture in certain examples of the 2021 model year Chevy Camaro, the 2019-2021 Chevy Malibu and select 2019-2021 model year Chevy and Buick crossover models.

The problem: affected vehicles may have been shipped with engine control module software that can lead to incorrect air-fuel enrichment in the engine. This problem only occurs under rare driving conditions.

The hazards: GM did not say if this can lead to any long-term issues or problems. A lean air-fuel mixture can potentially cause engine damage, however, while a rich mixture can lead to poor fuel economy and/or excess emissions.

The fix: dealerships will reprogram the engine control module. These repairs will be performed at no cost to the vehicle owner. This service update, first issued in June 2021, is active for all vehicles currently in dealership inventory and customer vehicles that return to the dealership in the future for any other reason. An over-the-air update is not possible to address this situation.

Affected vehicles:

Affected components: engine control module software.

Number of affected vehicles: GM did not say how many vehicles may be affected by this problem.

Next steps: owners of affected vehicles can have their vehicle ECU recalibrated at the dealership. These owners can also reach out to Chevy or Buick directly with any questions or concerns they may have using the contact information included below.


  • GM Service Update Number: N202321990
  • Chevrolet Customer Service: 1-800-222-1020
  • GMC Customer Service: 1-800-462-8782

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Sam McEachern: Sam loves to write and has a passion for auto racing, karting and performance driving of all types.

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