U1345: 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 U1345 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

3 complaints filed with NHTSA mention U1345, 3 of them since 2015, across 3 different models. The component owners most often filed it under: electrical system.

Manufacturer service bulletins that name U1345

11 technical service bulletins and manufacturer communications filed with NHTSA mention U1345, from 3 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • CHEVROLET SILVERADO 1500 (2023, 2022), bulletin 10239188: This Preliminary information communicates the possibility of dtc U060F or U1345 being set as current or history and clearing the codes then evaluating to confirm they do not return Engineering investigating root cause of…
  • GMC SIERRA 1500 (2022, 2023), bulletin 10239188: This Preliminary information communicates the possibility of dtc U060F or U1345 being set as current or history and clearing the codes then evaluating to confirm they do not return Engineering investigating root cause of…
  • CHEVROLET BOLT EV (2022), bulletin 10215671: This service bulletin provides repair information to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated and/or Driver Information Center (DIC) Displays Service Transmission Now, Unable to Shift …
  • CHEVROLET BOLT EUV (2022), bulletin 10216382: This Preliminary information communicates to the dealer if a vehicle comes in for an MIL or a message withDTC U1345 Engine Control Module LIN Bus 1 (or Bus 21) and/or DTC U135A that engineering is working on the issue an…
  • BUICK ENCLAVE (2019), bulletin 10162125: This Preliminary information communicatesSES lamp with DTC U1345. Inspect connection at the upper and lower Aero Shutters for water. Clean and repair as needed.
  • CHEVROLET TRAVERSE (2017, 2018, 2019), bulletin 10162125: This Preliminary information communicatesSES lamp with DTC U1345. Inspect connection at the upper and lower Aero Shutters for water. Clean and repair as needed.

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.