Fuel Trim Cell Diagnostic Weights
WARNING: This page is about a different car, the 2005 Suzuki Swift +, 2005 Pontiac Wave, and 2005 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.
No fuel trim DTC will set regardless of the fuel trim counts in cell 0 unless the fuel trim counts in the weighted cells are also outside specifications. This means that the vehicle could have a fuel trim problem which is causing a problem under certain conditions, i.e. engine idle high due to a small vacuum leak or rough due to a large vacuum leak, while it operates fine at other times. No fuel trim DTC would set, although an engine idle speed DTC or HO2S2 DTC may set. Use a scan tool to observe fuel trim counts while the problem is occurring.