U1001: 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 U1001 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

5 complaints filed with NHTSA mention U1001, 3 of them since 2015, across 5 different models. The component owners most often filed it under: service brakes.

Manufacturer service bulletins that name U1001

5 technical service bulletins and manufacturer communications filed with NHTSA mention U1001, from 3 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:

  • ISUZU N-SERIES (2022), bulletin 10214883: Dealers, upfitters or bodybuilders may notice various warning lights on the dash illuminating and certain DTCs without an apparent cause during the initial installation and connection of telematics, GPS, and/or other aft…
  • NISSAN ARMADA (2017), bulletin 10119192: 2017 ARMADA; MIL ON WITH P0090 AND U1000 AND/OR U1001 STORED IF YOU CONFIRM MIL is ON with the following DTC stored: - P0090 (FRP CONTROL SYSTEM) And U1000 and/or U1001 DTCs are stored in one or more other control units.…
  • INFINITI QX80 (2016, 2017), bulletin 10120548: 2016-2017 QX80; MIL ON WITH P0090 AND U1000 AND/OR U1001 STORED IF YOU CONFIRM MIL is ON with the following DTC stored: - P0090 (FRP CONTROL SYSTEM) And U1000 and/or U1001 DTCs are stored in one or more other control uni…
  • INFINITI EX35 (2008, 2009, 2010, 2011), bulletin 10192396: SERVICE INFORMATION Related to communication codes U1000, U1001, U1002, U1010: - Always diagnose the communication codes first. - When a module reports a U1000 code, it is typically operating normally; however, there is …
  • NISSAN 350Z (2005, 2006, 2007, 2008), bulletin 10192394: SERVICE INFORMATION Related to communication codes U1000, U1001, U1002, U1010: - Always diagnose the communication codes first. - When a module reports a U1000 code, it is typically operating normally; however, there is …

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.