U0401 on Honda Accord
Invalid Data Received From ECM/PCM A
Methodology: Reviewed against the SAE J2012 generic DTC definition and NHTSA owner-complaint patterns, then scoped to Honda Accord context without treating complaints as confirmed diagnoses.
Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).
- SAE J2012 Diagnostic Trouble Code Definitions — Generic diagnostic trouble code definition reference for U0401.
- NHTSA recalls, complaints, and manufacturer communications — Used to check public owner complaint context, recall status, and safety-related manufacturer communications by VIN or vehicle.
Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.
What U0401 Means on Your Honda Accord
U0401 is a diagnostic trouble code indicating: Invalid Data Received From ECM/PCM A. This code relates to the network communication system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Real Honda Accord Owner Reports
Source: NHTSA Complaints Database
"The issue first appeared during my initial test drive before purchase in 2019. The salesman stated it was a low-battery issue from the car sitting on the lot. Since then, the same problem has recurred multiple times."
"Began getting several alerts, when taken in to get a diagnosis I received the following error codes P0301, P0304, P0301, P0300, U0401-68 & U3003-16."
"CMS - collision mitigation system stops working completely. 2 warning lamps on dash. Cruise control completely inoperative."
All reports filed by vehicle owners directly with the U.S. Department of Transportation.
📊 Complaint Trend by Model Year
Common Causes on Honda Accord
Based on NHTSA complaint component analysis for this vehicle.
What To Do Next
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1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
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2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
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3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.