P0121 on Your 2024 Infiniti QX60
A P0121 on your 2024 Infiniti QX60 indicates the ECM has caught an irregular throttle position sensor signal. The voltage stays in range but doesn't match expected behavior—the detective in your engine computer has flagged the throttle body for closer examination.
The 2024 QX60 continues with the 3.5L V6 (VQ35DD) with direct injection and 9-speed automatic. Now in its third year on this platform, the powertrain has been refined through software updates, making a P0121 on this model year worth investigating promptly.
Symptoms
- Check engine light on
- Hesitation during acceleration
- Idle roughness
- Throttle feels less responsive
- Possible reduced power
Probable Causes
- ECM software calibration – Ongoing refinements for the VQ35DD platform. Likelihood: 35%
- Carbon deposits – DI engine carbon from city driving. Likelihood: 30%
- Throttle body defect – Manufacturing issue. Likelihood: 20%
- Connector issue – Factory connection problem. Likelihood: 10%
- Intake leak – Loose duct or gasket. Likelihood: 5%
Cost
- All repairs: $0 under warranty
- Out-of-warranty reference: Cleaning $100–$180, replacement $350–$600, software $100–$200
Infiniti Dealer Service
Your 2024 QX60 is fully covered under Infiniti's 4-year/60,000-mile basic warranty and 6-year/70,000-mile powertrain warranty. Take it to the dealer for free diagnosis and repair via Consult-III+.
How AutoDetective AI Can Help
Upload your QX60 scan data to AutoDetective for a free AI diagnosis specific to the VQ35DD platform.