P0175 on the 2022 Mercedes-Benz GLC (X253/X254)
Your 2022 Mercedes-Benz GLC has triggered a P0175 code, indicating bank 2 is running too rich. The 2022 model year was a transition period for the GLC: the outgoing X253 used the M264 2.0-liter turbo four-cylinder (255 hp), while the incoming X254 introduced the M254 2.0-liter turbo four-cylinder with updated 48-volt mild hybrid technology (258 hp). Both engines are four-cylinder turbo units with direct injection, and bank 2 refers to the rear cylinder pair. At two to four years old, most 2022 GLCs should still be within Mercedes-Benz's warranty coverage.
Symptoms
- Yellow check engine light
- Reduced fuel economy
- Dark or black exhaust smoke
- Rough idle
- Fuel smell from exhaust
- Possible performance reduction
Engine Generation Differences
If your 2022 GLC is the outgoing X253, it uses the M264 engine with a belt-driven starter-generator. If it is the new X254, it uses the M254 with an integrated starter-generator and electric auxiliary compressor. The diagnostic approach for P0175 is similar, but the X254's additional electric boost components add diagnostic considerations. Check your VIN or window sticker to determine which generation and engine your GLC has.
Common Causes
1. Bank 2 Lambda Sensor Degradation
The wideband lambda sensor on bank 2 is the most common P0175 cause on Mercedes vehicles. After two to four years, the sensor can develop measurement drift from heat cycling and exhaust exposure. Mercedes lambda sensors are precise instruments, and even minor degradation can push fuel trims past the P0175 threshold given the ECU's tight control parameters.
2. Fuel Injector Problem
Both the M264 and M254 use high-pressure direct injection. An injector on bank 2 with a seal issue, spray pattern defect, or carbon fouling adds improperly metered fuel. At this age, early carbon deposits on injector tips can begin to affect spray patterns.
3. Turbo System Issue
Wastegate actuator calibration drift or malfunction can cause inconsistent boost delivery. The M254's electric auxiliary compressor adds an additional component that can contribute to boost inconsistency. When boost delivery does not match the ECU's expectations, fuel enrichment can push bank 2 rich.
4. Intake System Problem
A leak in the charge air system, a faulty CAMTRONIC actuator (M254), or a contaminated MAF sensor can all affect how much air actually reaches the cylinders versus what the ECU calculates. Any discrepancy between actual and calculated airflow results in incorrect fuel delivery.
Diagnostic Process
- Use Mercedes XENTRY diagnostics to read all faults and adaptation data
- Identify whether you have the M264 (X253) or M254 (X254) engine
- Review lambda sensor adaptation and aging data for bank 2
- Monitor fuel trims at idle, cruise, and under boost
- Check turbo boost system operation and electric compressor function (X254)
- Test fuel rail pressure under various conditions
- Inspect charge air system for leaks
Warranty and Cost
Under warranty: $0 at Mercedes dealer. If out of pocket: Lambda sensor $350 to $700. Fuel injector $450 to $1,100. Turbo system repair $500 to $1,500. Mercedes dealer labor: $170 to $240/hour. The 2022 GLC should still be within the 4-year/50,000-mile warranty period for most owners.
Best-Selling Mercedes SUV
The GLC is Mercedes-Benz's top seller, which means dealers have extensive experience with both the M264 and M254 engines. This familiarity typically results in efficient diagnosis and repair. If your GLC is under warranty, the dealer is the clear best choice for P0175 repair.