Investigating the P0100 Code on Your 2022 Mercedes-Benz C-Class
When your 2022 Mercedes-Benz C-Class triggers a P0100 code, the engine control unit (ECU) has detected a malfunction in the mass airflow (MAF) sensor circuit. The W206-generation C-Class uses the M254 2.0-liter turbocharged engine with a 48V mild hybrid system, and this code indicates the MAF sensor is providing unreliable data to the sophisticated powertrain management system.
What P0100 Means
P0100 is a circuit malfunction code indicating erratic, intermittent, or out-of-range MAF sensor signals. The hot-film MAF sensor measures air entering the turbo intake, and the ECU uses this information alongside boost pressure, intake temperature, and EQ Boost status to optimize engine performance and emissions. When MAF data becomes unreliable, the ECU defaults to estimated values that reduce both performance and efficiency.
Common Symptoms
- Check engine light illuminated
- Reduced power warning on MBUX display
- Rough or uneven idle
- Reduced turbo boost and EQ Boost performance
- Increased fuel consumption
- Hesitation during acceleration
- Auto-start/stop may become inactive
- Possible limp mode
Top Causes Ranked by Likelihood
- MAF sensor contamination (30-35%) — Oil vapor from the crankcase ventilation and environmental contaminants accumulating on the sensing element
- Charge air leak (20-25%) — Crack or loose connection in the turbo intercooler piping
- Air filter or housing problem (15-20%) — Dirty, damaged, or improperly installed air filter
- Electrical connection fault (10-15%) — Corroded, loose, or damaged MAF sensor connector or wiring
- MAF sensor failure (10-15%) — Internal hot-film element degradation
Diagnostic Steps
Start with visual inspection. Check the air filter for contamination and proper seating. Verify the MAF sensor connector is fully seated with no visible corrosion. Inspect the charge piping between the intercooler and throttle body for cracks or loose connections.
Clean the MAF sensor with dedicated MAF sensor cleaner spray ($10-15). This inexpensive step resolves about 30-35% of P0100 cases. Remove the sensor carefully, spray the hot-film element without touching it, and allow complete drying.
For comprehensive diagnosis, Mercedes' XENTRY system provides the most detailed fault analysis, but third-party tools like iCarsoft MB or Star Diagnostic can also read Mercedes-specific fault codes and live data for the DIY approach.
Warranty Considerations
Your 2022 C-Class may still be within Mercedes-Benz's 4-year/50,000-mile warranty (through 2026). Check your odometer and contact your dealer to verify coverage. The federal emissions warranty covers the MAF sensor for 8 years/80,000 miles through 2030, providing extended protection even after the basic warranty expires.
Estimated Repair Costs
- MAF sensor cleaning: $10-15 (DIY)
- Air filter replacement: $30-50
- MAF sensor replacement: $250-500 (OEM part) + $120-200 (labor)
- Charge pipe repair: $100-300 (part) + $100-200 (labor)
- Wiring repair: $150-350