P0121 on Your 2022 Dodge Hornet: A New Platform Investigation
When your 2022 Dodge Hornet logs a P0121, the PCM has detected irregular throttle position sensor behavior. The TPS voltage is within range but the signal pattern is erratic—our detective has identified a discrepancy between what the accelerator pedal commands and what the throttle body reports. On the Hornet's turbocharged platform, precise throttle control is critical.
The Dodge Hornet is built on the Alfa Romeo Tonale platform and uses either a 2.0L turbocharged four-cylinder (Hurricane) producing 268 hp, or a 1.3L turbo-four plug-in hybrid (R/T PHEV). Both engines use direct fuel injection and electronic throttle control—a significant departure from Dodge's traditional Stellantis powertrains. The TPS is integrated into the throttle body assembly.
Symptoms to Watch For
- Check engine light on
- Turbo lag that seems excessive
- Hesitation during acceleration
- Rough or unsteady idle
- Throttle response feels inconsistent or delayed
Most Likely Causes
- Carbon buildup on throttle body – The 2.0L turbo's direct injection system is highly susceptible to carbon deposits on the throttle plate and bore. This is the #1 concern with DI turbo engines. Likelihood: 40%
- ECM software calibration – As a first-generation platform for Dodge, software updates for throttle mapping and boost management are expected. Likelihood: 25%
- Throttle body assembly defect – Manufacturing quality issues are possible on a new platform. The Alfa Romeo-sourced throttle body may have different reliability patterns than traditional Stellantis parts. Likelihood: 20%
- Boost system interaction – Wastegate or diverter valve issues affecting pressure at the throttle body. Likelihood: 10%
- Wiring or connector fault – Loose connector or wire routing issue from factory assembly. Likelihood: 5%
Estimated Repair Costs
- All repairs: $0 under warranty
- Out-of-warranty reference: Cleaning $80–$160, throttle body replacement $350–$600, software update $100–$200
Warranty Is Your Best Friend
Your 2022 Hornet is covered under Stellantis's 3-year/36,000-mile basic warranty and 5-year/60,000-mile powertrain warranty. Take it directly to your Dodge dealer. The Hornet uses wiTECH for diagnostics, though some Alfa Romeo-platform-specific procedures may also apply. Do not attempt DIY repairs—warranty coverage makes dealer service the clear choice.
How AutoDetective AI Can Help
The Hornet is a newer platform with limited repair pattern data. AutoDetective's AI cross-references Alfa Romeo Tonale data alongside Dodge Hornet reports to identify the most probable cause for your specific engine and mileage.