What Does P0121 Mean on a 2024 Dodge Hornet?
A P0121 on your 2024 Dodge Hornet indicates the PCM has caught an irregular throttle position sensor signal. The voltage is technically in range, but the pattern is off—like a detective reviewing surveillance footage where the timestamps don't line up. The electronic throttle body isn't communicating reliably with the engine computer.
The 2024 Hornet continues on the Alfa Romeo Tonale platform with the 2.0L turbocharged four-cylinder (Hurricane, 268 hp) or the 1.3L turbo-four plug-in hybrid (R/T PHEV). Both engines use direct fuel injection, making them inherently more susceptible to carbon-related throttle body issues than port-injection engines.
Symptoms You'll Notice
- Check engine light on
- Turbo response feels sluggish
- Hesitation or stumble on acceleration
- Idle feels rough or unstable
- Throttle pedal may feel unresponsive momentarily
Top Causes
- ECM software calibration – As a second-year platform, Stellantis is still refining throttle mapping and boost control software. This is the top suspect on a nearly-new vehicle. Likelihood: 35%
- Carbon deposits on throttle body – The DI turbo engine can accumulate carbon on the throttle plate surprisingly quickly, especially with short-trip city driving. Likelihood: 30%
- Throttle body manufacturing defect – The Alfa Romeo-sourced throttle body may have a factory fault in the TPS or motor assembly. Likelihood: 20%
- Connector or wiring issue – Loose factory connector or wire routing problem. Likelihood: 10%
- Boost system anomaly – Wastegate or diverter valve issues affecting throttle body pressure. Likelihood: 5%
Repair Cost
- All repairs: $0 under warranty
- Out-of-warranty reference: Cleaning $80–$160, replacement $350–$600, software update $100–$200
Go Straight to the Dealer
Your 2024 Hornet is fully covered under Stellantis's 3-year/36,000-mile basic warranty and 5-year/60,000-mile powertrain warranty. Do not attempt DIY repairs—take it to your Dodge dealer. The dealer will use wiTECH diagnostics to analyze the throttle system, check for Technical Service Bulletins specific to the Hornet platform, and apply any pending software updates at no cost.
How AutoDetective AI Can Help
AutoDetective's AI can analyze your 2024 Hornet's scan data against emerging platform patterns to give you an informed preview before your dealer visit. Upload your OBD-II data for a free preliminary diagnosis.