P0121 on Your 2022 Audi Q5: The Investigation
When your 2022 Audi Q5 sets a P0121, the ECM has flagged an irregular throttle position sensor signal pattern. The TPS voltage is within range but doesn't track your pedal inputs correctly—our detective has found the first clue that the electronic throttle body needs investigation.
The 2022 Q5 uses the 2.0L TFSI turbocharged four-cylinder (EA888 Gen 3B) producing 261 hp, paired with a 7-speed S tronic and Quattro AWD. The EA888's direct injection system is well-known for carbon accumulation patterns. The Q5 also offers a plug-in hybrid (Q5 PHEV) with the same base engine.
Symptoms
- Check engine light and EPC warning light
- Hesitation during acceleration, especially under load
- Rough idle
- Turbo boost feels muted
- Possible limp mode
Most Likely Causes
- Carbon buildup on throttle body – The EA888's DI system deposits carbon on the throttle plate and bore. At 2–4 years old, deposits are a primary suspect. Likelihood: 45%
- Throttle body assembly wear – Internal TPS or motor degradation within the electronic throttle body. Likelihood: 25%
- ECM software adaptation – Audi may have released calibration updates for the Q5's throttle management. Likelihood: 15%
- Wiring or connector corrosion – Heat from the turbo engine bay degrades connectors. Likelihood: 10%
- Diverter valve issue – The EA888's recirculating diverter valve can affect pressure dynamics at the throttle body. Likelihood: 5%
Repair Costs
- Throttle body cleaning: $100–$200 (shop) / $10–$25 (DIY)
- Throttle body replacement: $400–$700 parts and labor
- Software update: $100–$250 (dealer or VCDS-equipped shop)
- Wiring repair: $100–$300
Check Warranty First
Your 2022 Q5 may still be within Audi's 4-year/50,000-mile warranty depending on purchase date and mileage. If covered, take it to the dealer for free repair. If out of warranty, throttle body cleaning is moderate difficulty. The EA888 requires a VCDS or ODIS throttle body basic setting adaptation after cleaning—a battery disconnect alone won't fully reset the system. In VCDS: Engine > Basic Settings > Throttle Body Adaptation.
How AutoDetective AI Can Help
AutoDetective's AI understands the EA888 platform's carbon buildup patterns across all Audi models. Upload your scan data for a tailored diagnosis.