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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1074 (Engine Controls Diagnosis - 6.6L (LLY) (DTC P0653 To DTC P2228)) >> Diagnosis >> DTC P1094 >> Circuit Description

Circuit Description

WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The engine control module (ECM) uses the fuel rail pressure (FRP) sensor to determine fuel pressure to the fuel injectors. This is then compared to the calculated target fuel pressure as determined by the ECM. The ECM adjusts the FRP by modulating the duty cycle of the control driver of the fuel pressure regulator. Injector pulse duration is determined by the measured rail pressure and the target injection fuel into each cylinder. If a sensor circuit malfunction is detected, or the commanded fuel injection pump flow is not within the proper range for a given engine load and speed, DTC will be set.