The ability to electronically calculate the precise quantity of fuel required for specific situations is a feature in modern Mercedes with electronic engine controls. Your Mercedes actuators, including fuel injectors and the mass airflow sensor, play a significant role in delivering the precise amount of fuel needed for combustion. The mass airflow is designed with sensors that measure the quantity of air mass entering your vehicle’s engine.
The mass airflow sensor helps your engine to achieve the right air-to-fuel ratio. The typical air-to-fuel ratio for your Mercedes is about 14.7 ratio 1. A faulty mass airflow sensor may affect your vehicle’s ability to correctly measure fuel injection ratio, thereby affecting the overall performance of your vehicle. Discussed below are some of the symptoms of a faulty mass airflow sensor.
Symptoms of a Faulty Mass Airflow Sensor
Hesitation and jerking during acceleration
Vehicle hesitation, jerking, stalling, and other poor performances are signs that your Mercedes mass airflow sensor may be failing. These issues occur mostly when you are cruising down a street in the city or speeding on the highway. The outcome of such drivability issues may be dangerous and often leads to accidents. Therefore, you should examine your mass airflow sensor when you experience these signs.
Extremely rich air-fuel ratio
One common sign of a failing mass airflow sensor is the presence of a very rich air-fuel ratio. Each combustion cylinder in your Mercedes requires the right air-to-fuel ratio. Running on a rich air-fuel ratio means that your vehicle operates with inadequate air and excess fuel.
A Mercedes running rich may emit black smoke from the tailpipe. In addition, the vehicle’s fuel efficiency may be very poor, causing your car to consume more fuel. Rough idling and a glowing check engine light on the dashboard are common signs of a failing mass airflow sensor.
Mass airflow sensor wires coated with dirt
Your Mercedes mass airflow sensor may fail when dirt forms a coating layer around the wires, thereby impeding the sensor’s ability to correctly measure the airflow. A malfunctioning mass airflow sensor may send your Mercedes powertrain control module incorrect signals. If the mass airflow sensor gives a high value or overestimates the airflow, the PCM may release excess fuel than required.
Extremely lean airflow ratio
While a high airflow ratio may be bad for your Mercedes, running on a lean airflow ratio may also affect your vehicle’s performance. A lean airflow ratio indicates excess air and low fuel. If the mass airflow sensor gives a low value or underestimates the airflow, the PCM releases less fuel than required.
Although you may have improved fuel efficiency, running lean for too long may cause damage to your vehicle. It could also cause issues such as hard starting, the check engine light, and hard engine seizures. Your Mercedes engine may also experience hesitation or surging when accelerating.
Your OBD-II scanner displays code PO101
A code PO101 from decoding your check engine light with an OBD-II scanner represents mass airflow sensor performance/circuit range. Your Mercedes electronic controller uses data from the mass airflow sensor to determine the quantity of fuel that has to be injected to achieve a correct air-fuel ratio.
Mass airflow data is used in determining the required engine load. False data representation may affect your Mercedes traction control system. The PO101 code may be caused by a faulty, obstructed, or dirty mass airflow sensor and should be properly checked by a competent auto mechanic.
Motor Cars International for Your European Car Maintenance and Repairs
Is your Mercedes experiencing signs of a failing mass airflow sensor? Motor Cars International is here for you. We believe the excellent 
performance you enjoy from your vehicle depends on the quality of service it receives.
At Motor Cars International, we understand how important even basic service appointments are for your car. We provide high-quality European vehicle services, including MAF repairs, clutch repair, brake repair, oil leak repairs, and more. Our automotive technicians are certified and experienced in repairing different European brands, including Porsche, Mini, BMW, Audi, Land Rover, and Mercedes.
We are located in Bridgewater, MA, and also welcome drivers from Norton, Easton, Sharon, and Raynham. Please call or visit our shop today for your next service appointment!