What Does P0121 Mean on a 2024 Hyundai Tucson?
A P0121 code on your 2024 Hyundai Tucson directs our diagnostic investigation to the throttle position sensor (TPS). The sensor is communicating within the expected voltage range but with a pattern the ECM flags as abnormal—readings don't match calculated values from pedal input, airflow, and engine load.
The 2024 Tucson is built on Hyundai's N3 platform with multiple powertrain options: 2.5L MPI four-cylinder (187 hp), 1.6L Turbo GDI hybrid (227 hp combined), or 1.6L Turbo GDI plug-in hybrid (261 hp combined). The MPI engine keeps the throttle body naturally clean, while the turbo GDI powertrains are slightly more carbon-prone. All use electronic throttle control with an integrated TPS.
Common Symptoms to Watch For
- Check engine light on
- Hesitation during acceleration
- Rough or unstable idle
- 8-speed automatic or hybrid transmission feels off
- HTRAC AWD may not respond predictably
- Smart Cruise Control may behave erratically
Top Causes Ranked by Likelihood
- ECM software calibration (35%) – Calibration refinements are common on current-year vehicles. Cost: $0 under warranty.
- Throttle body manufacturing defect (30%) – Factory defect in the throttle body or TPS element. Cost: $0 under warranty.
- Wiring or connector defect (20%) – Assembly variability. Cost: $0 under warranty.
- Carbon buildup (10%) – Unlikely at low mileage; MPI engine is least susceptible. Cost: $120–$275 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. Schedule a dealer visit soon. Hyundai's comprehensive warranty makes this a no-cost repair.
Diagnostic Path
Take your 2024 Tucson to a Hyundai dealer. GDS diagnostics, TSB checks, and any repairs are fully covered under warranty.
Can You Fix This Yourself?
Your 2024 Tucson is covered by Hyundai's 5yr/60k basic warranty + 10yr/100k powertrain warranty (original owner). Dealer visit is free—use it.
Get a Free AI Diagnosis
Heading to the dealer? AutoDetective's free AI diagnosis gives you a head start on understanding your Tucson's P0121.