What Does P0121 Mean on a 2024 Nissan Frontier?
P0121 on your 2024 Nissan Frontier tells our diagnostic investigators that the throttle position sensor (TPS) is sending voltage within normal range but the pattern is abnormal. The ECM detects a mismatch between TPS readings and calculated expectations from pedal position, airflow, and engine load data.
The 2024 Frontier runs the 3.8L VQ38DD V6 (310 hp) with a 9-speed automatic. By 2024, the third-generation Frontier's calibrations are well-refined, making a P0121 on this model year more likely a hardware issue than a software one—though updates are still possible.
Common Symptoms to Watch For
- Check engine light on
- Hesitation during acceleration
- Rough or unstable idle
- Transmission shift quality degradation
- Reduced towing performance
- Off-road response feels unpredictable
Top Causes Ranked by Likelihood
- Throttle body manufacturing defect (30%) – A factory defect in the throttle body or TPS element. Cost: $0 under warranty.
- ECM software calibration (25%) – While the platform is more mature, updates are still released. Cost: $0 under warranty.
- Wiring or connector defect (20%) – Assembly variability in harness or connector. Cost: $0 under warranty.
- Carbon buildup on throttle body (15%) – The DI engine can produce deposits even at low mileage with certain driving patterns. Cost: $150–$300 if not covered.
- Intake system leak (10%) – A gasket or clamp issue. Cost: $0 under warranty.
How Serious Is This Code?
P0121 is medium severity. Resolve it soon, especially if you tow or haul regularly. Warranty covers everything.
Diagnostic Path
Take it to a Nissan dealer. CONSULT diagnostics, TSB checks, and any repairs are covered under warranty.
Can You Fix This Yourself?
Your 2024 Frontier is fully covered under Nissan's 3yr/36k basic and 5yr/60k powertrain warranties. Dealer visit is free—use it.
Get a Free AI Diagnosis
Know what to expect before your dealer appointment. AutoDetective's free AI diagnosis gives you a head start on understanding your Frontier's P0121.