P0120 on the All-New 2024 Infiniti QX80
The 2024 QX80 is a completely redesigned flagship SUV, and P0120 on a brand-new platform demands attention. This code indicates a throttle position sensor circuit malfunction. The all-new 2024 QX80 features a 3.5L twin-turbo V6 (replacing the legendary 5.6L V8), and its electronic throttle body integrates the TPS into the assembly. As a first-year model on an entirely new platform, early software or component issues are not uncommon — and the warranty covers them fully.
What You'll Experience
- Check engine light illuminated
- Power severely limited — failsafe mode
- Throttle response sluggish or absent
- Idle may be rough or unstable
- Multiple warning lights possible
Probable Causes
1. First-Year Throttle Body Component Issue
As a completely new platform with a new engine, first-year production vehicles may have throttle body components that are within manufacturing tolerance but develop issues early. This is the primary suspect.
2. New Engine Software Calibration
The 3.5L twin-turbo V6 is new to the QX80 and may need post-launch software calibrations to optimize throttle body adaptation and TPS signal processing.
3. Assembly Line Connector Issue
New production lines for redesigned vehicles sometimes have connector seating or harness routing issues that manifest after initial driving.
4. Twin-Turbo System Interaction
The twin-turbo system's boost control interacts closely with the throttle body. A communication issue between the boost controller and throttle system can generate P0120.
5. Pedal Sensor Calibration
The new pedal assembly for the redesigned QX80 may need a calibration update to align pedal sensor signals with the new throttle body parameters.
Diagnostic Steps
- Infiniti dealer scans with latest Consult-III+ software
- Check for TSBs specific to the 2024 QX80 redesign
- Verify all ECM modules at latest calibration level
- Inspect connector seating and harness routing
- Monitor live TPS, APP, and boost data
Repair Costs
- All repairs under warranty: $0
- Throttle body replacement (out of pocket): $450–$950
Can I Drive With P0120?
The all-new QX80 weighs over 6,000 lbs. In failsafe mode, it should not be driven in traffic. Use Infiniti roadside assistance for a tow to the dealer.
DIY vs Professional
Dealer only. Your 2024 QX80 is fully covered under Infiniti's 4-year/60,000-mile basic warranty and 6-year/70,000-mile powertrain warranty. All repairs are at no cost. First-year models on new platforms especially should be serviced by the dealer for proper documentation.
Frequently Asked Questions
Is the 2024 QX80 a new platform?
Yes. The 2024 QX80 is a ground-up redesign with a new 3.5L twin-turbo V6 replacing the 5.6L V8, new architecture, and completely new interior. It's mechanically unrelated to previous QX80 generations.
Is this a common first-year problem?
First-year models on new platforms occasionally have teething issues. The warranty specifically covers these situations. Keep all service records.
Will this affect my QX80's resale value?
A properly repaired P0120 with dealer documentation should not affect resale value. The repair is recorded in the vehicle's service history as a warranty item.
Can I request a different QX80 if this keeps happening?
If the issue recurs multiple times after repair, lemon law protections may apply depending on your state. Document all dealer visits and keep records of every repair attempt.