What Does P0121 Mean on a 2024 Hyundai Santa Fe?
A P0121 on your 2024 Hyundai Santa Fe directs our diagnostic investigation to the throttle position sensor (TPS). The sensor is communicating within normal voltage range but with an abnormal pattern that doesn't match the ECM's calculations from pedal input, airflow, and engine load.
The 2024 Santa Fe is a completely redesigned fifth generation on Hyundai's new platform. Powertrain options include the 2.5L Turbo GDI (277 hp) and a 1.6L Turbo GDI hybrid (232 hp combined). The shift to turbocharged engines across the lineup means direct injection is standard, making carbon awareness important even on new vehicles. 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
- 8-speed DCT or hybrid transmission feels off
- HTRAC AWD response unpredictable
- Highway Driving Assist may behave erratically
Top Causes Ranked by Likelihood
- ECM software calibration (40%) – First-year redesigns commonly need calibration updates. Cost: $0 under warranty.
- Throttle body manufacturing defect (25%) – New production components carry higher variability. Cost: $0 under warranty.
- Wiring or connector defect (20%) – New platform harness routing issues. Cost: $0 under warranty.
- Carbon buildup (10%) – Unlikely at low mileage, but turbo GDI can produce early deposits. Cost: $120–$300 if not covered.
- Intake or boost leak (5%) – Factory clamp or gasket issue. Cost: $0 under warranty.
How Serious Is This Code?
P0121 is medium severity. As a brand-new redesign, any driveability issue should be addressed promptly. Warranty covers everything. Schedule a dealer visit soon.
Diagnostic Path
Take your 2024 Santa Fe to a Hyundai dealer. First-year models benefit most from dealer diagnostics with access to the latest TSBs and calibration updates.
Can You Fix This Yourself?
Full warranty: 5yr/60k basic + 10yr/100k powertrain. Dealer visit is free and covers everything.
Get a Free AI Diagnosis
Prepare for your dealer visit. AutoDetective's free AI diagnosis gives you informed talking points about your Santa Fe's P0121.