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Home >> Buick >> 2019 >> Regal TourX Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 139 (Engine Controls And Fuel - 3.6L (LGX) - Diagnostic Information And Procedures (P0449-P3436) And Symptoms) >> Diagnostic Information and Procedures >> DTC P050D >> Circuit/System Description

Circuit/System Description

WARNING: This page is about a different car, the 2020 Buick Regal and 2019 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.

During a cold start, the engine control module (ECM) commands dual-pulse mode during Open Loop operation to improve cold start emissions. In dual-pulse mode, the fuel injectors are energized twice during each injection event. As with misfire diagnosis, in dual-pulse mode the ECM monitors the crankshaft position sensor and the camshaft position sensors to calculate crankshaft rotation speed. In normal operation, optimum fuel delivery during dual-pulse mode produces a steady crankshaft rotation speed. If the variations exceed a calibrated value, the DTC sets.

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