P0121 on the 2023 Dodge Charger: Final-Year LX Platform
A P0121 code on your 2023 Dodge Charger means the PCM has detected that the throttle position sensor signal pattern doesn't match the expected behavior. The voltage is in range but the trace is erratic—like our detective's prime suspect who's technically cooperating but whose story keeps changing. The electronic throttle body needs closer examination.
The 2023 Charger represents the final year of the iconic LX platform. Whether you have the 3.6L Pentastar V6, 5.7L Hemi, 6.4L SRT Hemi, or the supercharged 6.2L Hellcat, all use port fuel injection and Stellantis drive-by-wire throttle control. As the last of the line, this platform has benefited from years of refinements, but the fundamentals of throttle body maintenance remain.
What You'll Experience
- Check engine light on
- Possible reduced throttle response
- Hesitation or stumble during acceleration
- Idle speed may fluctuate
- MDS cylinder deactivation may behave erratically (Hemi models)
The Case File: Likely Causes
- Carbon contamination on throttle body – Even on a relatively new vehicle, PCV vapors and intake tract deposits can foul the throttle plate. City driving and short trips accelerate this. Likelihood: 40%
- Throttle body assembly issue – Internal TPS or motor component failure. Likelihood: 25%
- PCM software update needed – Stellantis released calibrations for the final-year LX platform. Likelihood: 15%
- Wiring or connector problem – Heat exposure, vibration, or corroded terminals at the throttle body plug. Likelihood: 15%
- Intake air leak – Loose air intake duct or throttle body gasket. Likelihood: 5%
Repair Cost Estimates
- Throttle body cleaning: $80–$150 (shop)
- Throttle body replacement: $250–$500 parts and labor
- PCM software update: $100–$180 (dealer)
- Wiring repair: $100–$250
Warranty Coverage
Your 2023 Charger should still be well within Stellantis's 3-year/36,000-mile basic warranty and 5-year/60,000-mile powertrain warranty. Take it to your Dodge dealer—this repair should be covered. The dealer will use wiTECH to diagnose the throttle body, perform a relearn, and apply any applicable software updates. Given this is the final-year LX Charger, maintaining proper service records through the dealer is especially valuable for resale.
How AutoDetective AI Can Help
Run your diagnostic data through AutoDetective before your dealer visit. Our AI will analyze your 2023 Charger's freeze frame data and engine variant to give you an informed preview of the likely diagnosis.