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DTC codes / P2Axx · Hybrid propulsion / P2AA3

P2AA3Cold Start EGR B Flow Insufficient Detected

P2AA3 indicates that during a cold start, the engine computer detected insufficient exhaust gas recirculation (EGR) flow through the EGR circuit designated as 'B'. The powertrain control module commands the EGR valve to open and monitors the resulting change in intake manifold pressure or mass airflow, and it sets this code when the expected flow increase does not occur within the calibrated time window.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaHybrid propulsion

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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