Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Isuzu >> 2008 >> Ascender LS, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 249 (Engine Control System & Fuel System - 4.2L - DTC P0366 T0 DTC P2544) >> DTC P1174 >> Circuit/System Description

Circuit/System Description

WARNING: This page is about a different car, the 2009 GMC Envoy and 2009 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.

The Fuel Trim Cylinder Balance diagnostic detects a rich or a lean cylinder-to-cylinder air/fuel ratio imbalance. The diagnostic monitors the pre-catalyst heated oxygen sensor (HO2S) signal's frequency and amplitude characteristics by calculating an accumulated voltage over a predetermined sample period. An imbalance is indicated when multiple samples of the accumulated voltage are consistently higher than the desired value.