Code Definition

P200B — Air Flow Sensor Volume Signal Error/Out of Range

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Mercedes-Benz

About P200B

P200B is a generic (obd-ii standard) powertrain diagnostic trouble code recorded for Mercedes-Benz vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P200B is stored, the module has detected a signal or supply voltage lower than the expected operating range; a plausibility fault — the measured value is in the electrical range but is not consistent with expected operating behaviour; and a sensor-related fault — the reported value from the named sensor is out of spec.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P200B is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The Engine Control Module (ECM) sets this code when it detects an implausible or out-of-range signal from the Mass Air Flow (MAF) sensor. The MAF sensor measures the amount of air entering the engine to ensure proper fuel delivery. A faulty sensor, wiring issue, or air intake restriction can cause incorrect airflow readings, leading to poor engine performance.

Quick Facts