What Does P0121 Mean on a 2024 Hyundai Kona?
A P0121 code on your 2024 Hyundai Kona tells our diagnostic investigators that the throttle position sensor (TPS) is transmitting voltage within the expected range but following an abnormal pattern. The ECM detects TPS data that doesn't correlate with pedal position, airflow, and engine load calculations.
The 2024 Kona is a completely redesigned second generation, now powered by the 2.0L MPI four-cylinder (147 hp) with a CVT. The MPI (port injection) engine keeps the throttle body and intake valves cleaner than direct-injection alternatives. As a first-year redesign, calibration refinements are expected.
Common Symptoms to Watch For
- Check engine light on
- Hesitation during acceleration
- Rough or unstable idle
- CVT feels jerky or unresponsive
- Smart Cruise Control may behave erratically
- Reduced fuel economy
Top Causes Ranked by Likelihood
- ECM software calibration (40%) – First-year redesigns commonly need software updates. Cost: $0 under warranty.
- Throttle body manufacturing defect (25%) – New production variability. Cost: $0 under warranty.
- Wiring or connector defect (20%) – New platform harness issues. Cost: $0 under warranty.
- Carbon buildup (10%) – Unlikely at low mileage, and MPI further reduces risk. Cost: $120–$250 if not covered.
- Intake system leak (5%) – Factory clamp or gasket issue. Cost: $0 under warranty.
How Serious Is This Code?
P0121 is medium severity. On a compact crossover with a modest engine, throttle lag is immediately noticeable. Schedule a dealer visit soon—it's free under warranty.
Diagnostic Path
Take your 2024 Kona to a Hyundai dealer. First-year redesigns benefit most from dealer GDS diagnostics with TSB access.
Can You Fix This Yourself?
Full Hyundai warranty: 5yr/60k basic + 10yr/100k powertrain (original owner). Dealer visit is free.
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