P0121 on the 2024 Mitsubishi Eclipse Cross
When your 2024 Mitsubishi Eclipse Cross sets P0121, the ECM has detected an inconsistent throttle position sensor pattern. The data is within voltage limits but doesn't match expectations—the throttle body needs investigation.
The 2024 Eclipse Cross continues with the 1.5L turbocharged four-cylinder DI engine (152 hp) and CVT. On a new vehicle, software calibration leads the suspect list, with the DI turbo engine's carbon tendency as a secondary factor.
Symptoms
- Check engine light on
- Turbo lag or hesitation
- Idle roughness
- CVT jerkiness
- Throttle response delayed
Probable Causes
- ECM software calibration – Mitsubishi platform refinements. Likelihood: 35%
- Carbon deposits – DI turbo carbon from city driving. Likelihood: 30%
- Throttle body defect – Manufacturing issue. Likelihood: 20%
- Connector issue – Factory problem. Likelihood: 10%
- Boost anomaly – Wastegate or piping. Likelihood: 5%
Cost
- All repairs: $0 under warranty
- Out-of-warranty reference: Cleaning $80–$150, replacement $250–$450, software $80–$150
Mitsubishi's Warranty Covers It
Your 2024 Eclipse Cross is fully covered under Mitsubishi's 5-year/60,000-mile basic and 10-year/100,000-mile powertrain warranties. Take it to the dealer for free diagnosis and repair.
How AutoDetective AI Can Help
Upload your Eclipse Cross's scan data to AutoDetective for a free AI diagnosis tailored to the 1.5L turbo platform.