U3003 — manufacturer-specific network / communication code

U3003 is a manufacturer-specific network / communication code: it is defined by the carmaker, not by the OBD-II standard, so the same code can mean different things on different brands. Below are the vehicles and failure patterns where owners report it, drawn from NHTSA complaints — the most reliable guide to what it means in practice.

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In our record, U3003 is reported most often on Ford, Mazda and Honda vehicles , against electrical and powertrain failure patterns , across 2012–2019 model years.

In ProblemsByVin's analysis of the NHTSA owner-complaint record, owners cite U3003 across 6 vehicle failure patterns. Diagnostic codes in complaints are reported by owners and are unverified — they point to where this code shows up, not a confirmed diagnosis. Open a page below for the full pattern (symptoms, mileage, repair costs owners cite).

Vehicles where owners report U3003 6 patterns

2019 Ford Ranger

electrical — Electronic power steering assist (EPAS) failure with battery voltage issue

2018 Honda CR-V

powertrain — Loss of power/limp mode/fuel system malfunction

2018 Mazda Mazda3

electrical — Parking brake light illumination with power loss and forward-sensing system false engagement

2014 Ford Fusion

electrical — Engine stalling and loss of power while driving

2013 Ford Explorer

powertrain — Transmission Failure (Mechanical / Internal Damage)

2012 Mazda Mazda3

electrical — Electrical system dropout / power loss event

Codes are pulled from what owners wrote in their NHTSA filings — they're allegations, not a shop diagnosis. Always confirm with a live scan. Browse all diagnostic codes →