P0299 on Honda Accord
Turbocharger/Supercharger A Underboost Condition
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 P0299.
- 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 P0299 Means on Your Honda Accord
P0299 is a diagnostic trouble code indicating: Turbocharger/Supercharger A Underboost Condition. This code relates to the fuel injection 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
"While accelerating uphill approximately 65 mph the car suddenly started to shutter and slow down to 35 mph. I forced me to move rapidly over to the right lane on a busy highway almost getting hit by a semi truck. Luckily I was able move to the shoulder and park the vehicle."
"Scanned for codes. Found P0303, P0299, and P2243 stored. Found coolant entering cylinder 3. Found excessive play in the waste gate rod and found A/F sensor is not responding. Needs head gasket. Vehicle starts up and runs rough. All alerts on alerts on dash on cust states check engine light on."
"The turbo! Code P0299! Hundreds of thousands of Americans going through the same issue all their lights are flashing on their dashboard with these 1."
"Subject: Turbocharger Underboost – Safety Concern on 2020 Honda Accord EX-L I am reporting a serious safety issue with the turbocharger system on my 2020 Honda Accord EX-L with the 1.5L turbocharged engine."
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.