P0121 on Your 2024 Acura TLX Explained
A P0121 code on your 2024 Acura TLX indicates the ECM has caught an irregular throttle position sensor pattern. The signal voltage is within bounds but doesn't match the expected correlation with your pedal inputs—our detective has flagged a throttle body communication issue that needs resolution.
The 2024 TLX offers the 2.0L VTEC turbo-four or the Type S's 3.0L twin-turbo V6, both with direct injection. On a vehicle this new, P0121 is more likely a software issue or manufacturing defect than wear-related carbon buildup, though short-trip driving can accelerate deposits even on low-mileage vehicles.
Symptoms
- Check engine light on
- Subtle hesitation during acceleration
- Idle quality slightly below TLX standards
- Throttle response may feel delayed or inconsistent
- Turbo may feel less responsive
Probable Causes
- ECM software calibration – Honda/Acura continues to refine throttle and boost management software. Likelihood: 35%
- Carbon deposits – DI turbo engines can accumulate deposits quickly with city driving. Likelihood: 25%
- Throttle body defect – Manufacturing quality issue. Likelihood: 25%
- Connector or wiring issue – Factory connection problem. Likelihood: 10%
- Boost system anomaly – Turbo or wastegate issue affecting throttle body. Likelihood: 5%
Cost
- All repairs: $0 under warranty
- Out-of-warranty reference: Cleaning $100–$180, replacement $350–$650, software $100–$200
Take It to Acura
Your 2024 TLX is fully covered under Acura's 4-year/50,000-mile basic warranty and 6-year/70,000-mile powertrain warranty. Take it to the dealer—all repairs are at no cost. The dealer will use Honda Diagnostic System for complete throttle analysis, software updates, and hardware replacement if needed.
How AutoDetective AI Can Help
AutoDetective's AI analyzes your 2024 TLX's specific engine and freeze frame data. Upload your scan results for a free diagnosis before your dealer appointment.