What Does P0121 Mean on a 2023 Hyundai Palisade?
P0121 on your 2023 Hyundai Palisade means the throttle position sensor (TPS) is operating within the expected voltage range but generating an abnormal signal pattern. The ECM finds that TPS data doesn't match its calculations from pedal input, airflow, and engine load.
The 2023 Palisade received a significant refresh with updated styling and the 3.8L Lambda II V6 (291 hp) continuing with an 8-speed automatic. The port-injected V6 naturally keeps the throttle body cleaner than DI alternatives. As a refreshed model year, calibration updates are particularly relevant.
Common Symptoms to Watch For
- Check engine light on
- Hesitation during acceleration
- Rough idle
- Transmission shifting feels off
- HTRAC AWD response unpredictable
- Highway Driving Assist may disengage
Top Causes Ranked by Likelihood
- ECM software calibration (35%) – Refreshed models often receive software updates. Cost: $0 under warranty.
- Throttle body manufacturing defect (25%) – Factory quality issue. Cost: $0 under warranty.
- Wiring or connector issue (20%) – Assembly variability. Cost: $0 under warranty.
- Carbon buildup (15%) – Low mileage, port injection—unlikely but possible with short-trip driving. Cost: $150–$300 if not covered.
- Intake system leak (5%) – Gasket or vacuum issue. Cost: $0 under warranty.
How Serious Is This Code?
P0121 is medium severity. Your flagship SUV deserves flawless operation. Warranty covers everything—schedule a visit soon.
Diagnostic Path
Dealer visit with GDS diagnostics. Full warranty coverage makes this a no-cost repair.
Can You Fix This Yourself?
Full Hyundai warranty: 5yr/60k basic + 10yr/100k powertrain (original owner). Take it to the dealer.
Get a Free AI Diagnosis
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