General Information

Engine Control
P2097 Post Catalyst Fuel Trim System Too Rich (Bank 1) - General Information

General Description

In order to provide the best possible combination of driveability, fuel economy, and emission control, the PCM uses a closed loop air/fuel metering system. The PCM monitiors the HO2S signal voltage and adjusts the fuel delivery based on the HO2S signal voltage in closed loop fuel control. Changes in fuel delivery will be indicated by the short-term and the long-term fuel trim values. The ideal fuel trimvalue is around 0%. The PCMwill add fuel when the HO2S signal is indicating a lean condition. Additional fuel is indicated by fuel trim values that are above 0%. The PCM will reduce fuel when the HO2S signal is indicating a rich condition. Reduction in fuel is indicated by fuel trim values that are below 0%. The DTC relevant to fuel trim will be set when the value reaches excessive levels because of a lean or rich condition.

DTC Description

The PCM monitors the trim of lambda control by the rear HO2S signal in addition to the HO2S monitoring. The trim value calculation is based on the difference of rear HO2S signal from desired value. The PCM sets DTC P2097 if either trim value or the difference of rear HO2S from desired value is reached to the minimum threshold. If the same error code is set in the next driving cycle, the PCM illuminates the MIL.

DTC Detecting Condition





Signal Waveform