P0121 on the Redesigned 2024 Buick Enclave
When your 2024 Buick Enclave sets a P0121, the ECM has detected an inconsistent throttle position sensor signal. The voltage is within range but the pattern is irregular—our detective has flagged the throttle body as the focus of investigation.
The 2024 Enclave is completely redesigned on a new platform, powered by a 2.5L turbocharged four-cylinder with direct injection, replacing the previous 3.6L V6. This is a significant powertrain change—the DI turbo engine is inherently more susceptible to carbon-related throttle issues than the old port-injection V6. Being a first-year redesign, software calibration is also a key consideration.
Symptoms
- Check engine light with possible Reduced Engine Power
- Turbo lag that seems excessive
- Hesitation on acceleration
- Idle roughness
- Throttle response inconsistency
Most Likely Causes
- ECM software calibration – First year on a new platform with a new engine. Software updates are expected and common. Likelihood: 40%
- Carbon deposits on throttle body – The new 2.5L turbo DI engine can accumulate carbon quickly with city driving. Likelihood: 25%
- Throttle body manufacturing defect – New platform quality issues are possible. Likelihood: 20%
- Connector or wiring issue – Factory assembly problem. Likelihood: 10%
- Boost system interaction – Turbo or wastegate anomaly. Likelihood: 5%
Cost
- All repairs: $0 under warranty
- Out-of-warranty reference: Cleaning $80–$160, replacement $300–$550, software $100–$180
Dealer Service Only
Your 2024 Enclave is covered under GM's 3-year/36,000-mile bumper-to-bumper and 5-year/60,000-mile powertrain warranty. As a first-year redesign, the dealer may have platform-specific TSBs already. Take it in for free diagnosis and repair. The dealer will use GDS2 for throttle system analysis and software updates.
How AutoDetective AI Can Help
AutoDetective's AI is tracking early patterns on the 2024 Enclave's new 2.5L turbo platform. Upload your scan data for a free analysis before your dealer visit.