Understanding P0121 on the 2024 Infiniti Q50
A P0121 on your 2024 Infiniti Q50 means the ECM has detected an abnormal throttle position sensor pattern. The voltage is in range but behaves erratically—our detective notes the throttle body isn't accurately tracking your pedal inputs.
The 2024 Q50 continues with the 3.0L twin-turbo V6 (VR30DDTT) in 300 hp or 400 hp Red Sport configurations, both with direct injection. This long-running platform is well-refined, making a P0121 on a 2024 model noteworthy. Software and manufacturing quality are the primary diagnostic considerations alongside the DI engine's inherent carbon susceptibility.
Symptoms
- Check engine light on
- Hesitation during acceleration
- Turbo response diminished
- Idle roughness
- Sport mode throttle feels inconsistent
Top Causes
- ECM software calibration – Ongoing VR30 platform refinements. Likelihood: 35%
- Carbon deposits – DI twin-turbo carbon from city driving. Likelihood: 30%
- Throttle body defect – Manufacturing issue. Likelihood: 20%
- Connector issue – Factory connection problem. Likelihood: 10%
- Boost system interaction – Wastegate or piping issue. Likelihood: 5%
Cost
- All repairs: $0 under warranty
- Out-of-warranty reference: Cleaning $100–$200, replacement $400–$700, software $100–$200
Dealer Service
Your 2024 Q50 is fully covered under Infiniti's 4-year/60,000-mile basic and 6-year/70,000-mile powertrain warranties. Take it to the dealer for free diagnosis and repair via Consult-III+.
How AutoDetective AI Can Help
Upload your Q50's scan data to AutoDetective for a free AI analysis specific to the VR30DDTT platform and your power level.