U3003 — OBD-II trouble code

A network / communication OBD-II trouble code. Below are the vehicles and failure patterns where owners report it, drawn from NHTSA complaints.

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 →