Code Definition

P049B — EGR Flow insufficient Bank 2

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

About P049B

P049B is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P049B is stored, the module has detected a signal or supply voltage lower than the expected operating range; and a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine.

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 P049B 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 fault code P049B is set when the Engine Control Module (ECM) detects insufficient exhaust gas recirculation (EGR) flow in Bank 2 of the engine. This condition suggests that the EGR system is not recirculating enough exhaust gas into the combustion chamber. Proper EGR flow is essential for reducing NOx emissions and improving engine efficiency by lowering combustion temperatures. In Bank 2, insufficient EGR flow can lead to increased emissions, reduced fuel efficiency, and potential engine performance issues.

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