U18A2: owner reports and bulletins

Network / communication. We haven't written the explanation for this code yet. Below is what owners and manufacturers have filed with NHTSA.

Got U18A2 on your scanner? Tell the mechanic your year, make, model and any symptoms and you'll get the likely cause and what to check first. Ask about this code.

What owners report to NHTSA

9 complaints filed with NHTSA mention U18A2, 9 of them since 2015, across 6 different models. The component owners most often filed it under: fuel/propulsion system.

Most-reported models

VehicleComplaintsModel years reported
CHEVROLET EQUINOX42019, 2020

Manufacturer service bulletins that name U18A2

21 technical service bulletins and manufacturer communications filed with NHTSA mention U18A2, from 3 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • CHEVROLET MALIBU (2020, 2021, 2022, 2023), bulletin 10251352: This service bulletin provides repair information to correct a customer concern of Service Engine Soon Illuminated in DIC and/or a Malfunctioning Fuel Gauge with DTC U0076/U18A2/P1001/P1434 or Other Message Counter Incor…
  • CHEVROLET EQUINOX (2020), bulletin 10172284: This technical bulletin is providing a procedure to reprogram the ECM to correct a condition of Runs Rough Cold or Stall Condition Upon Cold Start and/or DTC U18A2 Set (Mexico Only) due to software concerns.
  • GMC TERRAIN (2020), bulletin 10172284: This technical bulletin is providing a procedure to reprogram the ECM to correct a condition of Runs Rough Cold or Stall Condition Upon Cold Start and/or DTC U18A2 Set (Mexico Only) due to software concerns.
  • GMC SIERRA 1500 (2019), bulletin 10167474: N192267870 - Service Update. Certain vehicles have a new feature that notifies customers via text or email of a low battery voltage. This feature will not function if the voltage becomes low and the vehicles is In Off Po…
  • CHEVROLET SILVERADO 1500 (2019), bulletin 10167474: N192267870 - Service Update. Certain vehicles have a new feature that notifies customers via text or email of a low battery voltage. This feature will not function if the voltage becomes low and the vehicles is In Off Po…
  • CADILLAC ESCALADE (2015, 2016, 2017, 2018), bulletin 10137723: This Preliminary Information communication provides information to the technician about vehicle that may have a Service Engine Soon Malfunction Indicator Lamp on. Technician may find Diagnostic Trouble Codes P2635, U0074…

Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.