O2 Sensor Signal Biased/Stuck Rich Bank 1 Sensor 2
Table of contents
P2271 MERCEDES-BENZ Possible Causes
- Faulty Heated Exhaust Gas Oxygen Sensor
- Heated Exhaust Gas Oxygen Sensor harness is open or shorted
- Heated Exhaust Gas Oxygen Sensor circuit poor electrical connection
- Air Intake Leaking (Metered Side)
- Fuel Pressure
How do I fix code P2271 MERCEDES-BENZ?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- Mercedes Benz Code = 0510 (Right O2 sensor, after TWC): Aging (P2271)
Cost of diagnosing the P2271 MERCEDES-BENZ code
The cost of diagnosing the P2271 MERCEDES-BENZ code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
P2271 MERCEDES-BENZ Description
This fault code is stored in the Engine Control Module (ECM) when an anomaly is detected with the oxygen sensor biased voltage. The control module will supply the oxygen sensor with a voltage, normally between 400 and 700 millivolts. Once the oxygen sensor’s operating conditions have been met and the sensor is operating at normal temperature, the sensor will pull down the biased voltage indicating a lean mixture and pull up the biased voltage indicating a rich mixture. The control module can now enter closed loop control and adjust engine fuelling accordingly. The signal wire must be inspected for open circuit or short to ground/positive. A faulty sensor may not be able to alter the biased voltage, so sensor operating should also be tested.