P0121 on Your 2024 Volvo XC40
A P0121 on your 2024 Volvo XC40 signals that the ECM has caught an irregular throttle position sensor pattern. The voltage is within limits but the behavior doesn't match expectations—the throttle body needs investigation.
The 2024 XC40 continues on the CMA platform with the 2.0L Drive-E turbo (B4/B5 mild-hybrid configurations) using direct injection. On a vehicle this new, software calibration is the top consideration alongside the DI engine's carbon tendencies.
Symptoms
- Check engine light on
- Hesitation on acceleration
- Idle roughness
- Turbo response muted
- Throttle response delayed
Top Causes
- ECM software calibration – Volvo CMA platform refinements. Likelihood: 40%
- Carbon deposits – DI turbo carbon from city commuting. Likelihood: 25%
- Throttle body defect – Manufacturing issue. Likelihood: 20%
- Connector issue – Factory assembly problem. Likelihood: 10%
- Boost system anomaly – Turbo or piping issue. Likelihood: 5%
Cost
- All repairs: $0 under warranty
- Out-of-warranty reference: Cleaning $100–$180, replacement $350–$600, software $100–$250
Volvo Dealer Service
Your 2024 XC40 is fully covered under Volvo's 4-year/50,000-mile warranty. All P0121 diagnosis and repairs are at no cost via VIDA diagnostics.
How AutoDetective AI Can Help
Upload your XC40's scan data to AutoDetective for a free AI diagnosis specific to the CMA platform.