P0120 on Your 2024 Infiniti Q50
Your 2024 Q50's twin-turbo V6 has gone from sport sedan to slug — and P0120 is the code telling you why. This throttle position sensor circuit malfunction means the ECU is receiving abnormal voltage from the VR30DDTT's electronic throttle body. On a vehicle under full factory warranty, this is a dealer-handled situation, but knowing the code helps you understand what's happening.
Symptoms
- Check engine light on
- Power severely reduced — limp mode
- Throttle response dead or laggy
- Idle instability
- Sport mode and dynamic controls may deactivate
Likely Causes
1. Throttle Body Defect
On a low-mileage 2024 model, an internal throttle body defect is the primary suspect. The VR30DDTT's throttle body handles significant airflow and must maintain tight tolerances.
2. ECM Software Calibration
A pending ECM update may address throttle adaptation parameters. Infiniti regularly releases post-production calibrations.
3. Connector or Wiring Issue
An improperly seated connector or pinched wire from assembly can cause intermittent TPS signal faults.
4. Turbo System Interaction
The twin-turbo boost control system interacts with the throttle body. A communication issue between these systems can trigger P0120.
5. Pedal Sensor Defect
A factory-defective accelerator pedal position sensor producing conflicting signals.
Diagnostic Steps
- Infiniti dealer scans with Consult-III+ for full diagnostics
- Check for TSBs on 2024 Q50 VR30DDTT throttle system
- Verify software calibration levels
- Inspect connector seating and wiring
- Monitor live TPS, APP, and boost data
Repair Costs
- All repairs under warranty: $0
- Throttle body replacement (out of pocket): $400–$800
Can I Drive With P0120?
Not at the Q50's normal performance level. Limp mode severely limits the twin-turbo V6. Drive cautiously to the nearest Infiniti dealer or use roadside assistance for a tow.
DIY vs Professional
Dealer only. Your 2024 Q50 is under Infiniti's 4-year/60,000-mile basic warranty. All throttle system repairs are covered at no cost. Do not void warranty coverage with DIY attempts.
Frequently Asked Questions
Is the 2024 Q50 still the same generation?
Yes. The 2024 Q50 continues on the same V37 platform with the VR30DDTT twin-turbo V6 that's been in production since 2016. It's a mature, well-known engine.
Will Infiniti warranty cover this?
Yes. The 4-year/60,000-mile basic warranty covers all throttle system components. The 6-year/70,000-mile powertrain warranty provides additional coverage.
Is the Q50 being discontinued?
While the Q50 is expected to be replaced eventually, the 2024 model is fully supported with warranty coverage, parts availability, and dealer service.
Can this issue affect the Q50's turbo system?
P0120 itself doesn't damage the turbos. The limp mode that activates actually protects the turbo system by limiting boost and airflow until the throttle issue is resolved.