P0121 on Your 2022 Infiniti Q50: Tracking Down the Issue
When your 2022 Infiniti Q50 throws a P0121, the ECM has detected an abnormal throttle position sensor signal. The voltage is within range but the pattern doesn't track your pedal inputs—our detective has found a lead that the electronic throttle body needs investigation.
The 2022 Q50 is powered by the 3.0L twin-turbo V6 (VR30DDTT) with direct injection, producing 300 hp (LUXE) or 400 hp (Red Sport 400). This high-performance DI twin-turbo engine demands precise throttle control for managing boost from two turbochargers. The electronic throttle body uses integrated dual TPS signals.
Symptoms
- Check engine light on
- Hesitation during spirited acceleration
- Turbo response feels diminished
- Idle roughness
- Throttle may feel less responsive in Sport mode
Most Likely Causes
- Carbon buildup on throttle body – The VR30DDTT's direct injection is prone to carbon deposits. The twin-turbo setup's high airflow accelerates accumulation. Likelihood: 45%
- Throttle body assembly wear – The performance-oriented throttle body's TPS or motor can degrade. Likelihood: 25%
- ECM software update – Nissan/Infiniti has released recalibrations for the VR30 platform. Likelihood: 15%
- Wiring or connector corrosion – Twin-turbo engine bay heat accelerates degradation. Likelihood: 10%
- Boost system interaction – Wastegate or bypass valve issue affecting throttle body pressure. Likelihood: 5%
Repair Costs
- Throttle body cleaning: $100–$200 (shop) / $10–$25 (DIY)
- Throttle body replacement: $400–$700 parts and labor
- ECM update: $100–$200 (dealer)
- Wiring repair: $100–$300
Warranty & DIY
Your 2022 Q50 should be within Infiniti's 4-year/60,000-mile basic warranty depending on mileage. The 6-year/70,000-mile powertrain warranty should apply. If out of basic warranty, throttle body cleaning is moderate difficulty on the VR30 engine. The dealer uses Consult-III+ for diagnostics and throttle body relearn procedures.
How AutoDetective AI Can Help
AutoDetective's AI understands the VR30DDTT platform's twin-turbo throttle patterns. Upload your scan data for a free diagnosis specific to your Q50's power level (300 or 400 hp).