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P0128 on HYUNDAI ELANTRA

Severity
High
NHTSA Reports
2
Most Affected
2017, 2018

What P0128 Means on Your HYUNDAI ELANTRA

Real HYUNDAI ELANTRA Owner Reports (Source: NHTSA Complaints Database)

"Check engine light came on while driving to dealership for an unrelated recall on door handle. A diagnosis of the car computer showed a code of P0128 Coolant Thermostat."

— 2017 HYUNDAI ELANTRA owner • ENGINE • Filed 12/07/2021

"Initial Fault Code: P0303 Replaced all 4 spark plugs and all 4 ignition coils. The check engine light extinguished momentarily but returned, logging P0303 and a new P0301 Replaced all 4 fuel injectors. CEL extinguished momentarily and then returned, logging P0303."

— 2018 HYUNDAI ELANTRA owner • ELECTRICAL SYSTEM,ENGINE,FUEL/PROPULSION SYSTEM • Filed 04/01/2025 ⚠️ Crash reported

Data from NHTSA Vehicle Complaints Database. All reports are filed by vehicle owners directly with the U.S. Department of Transportation.

Common Causes of P0128 on HYUNDAI ELANTRA

50%
50%

Percentages based on NHTSA complaint component analysis for this vehicle.

Complaint Trend by Year

2017
1
2018
1

What To Do Next

  1. 1
    Check for recalls on YOUR VIN

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if your vehicle is covered.

  2. 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.

  3. 3
    Compare repair quotes

    Get 2-3 quotes. Dealer vs independent shop prices often differ 30-50% for the same repair.

P0128 on Other Vehicles

Data sourced from the National Highway Traffic Safety Administration (U.S. Department of Transportation) and the SAE J2012 OBD-II standard. Code definitions follow the SAE J2012 / ISO 15031-6 standard. Owner reports are filed directly with NHTSA by vehicle owners. This information is provided for educational purposes only and should not replace professional automotive diagnosis. Always consult a qualified mechanic for vehicle repair decisions.

Last updated: March 2026