P2096
P2096General Description
In order to provide the best possible combination of drivability, fuel economy, and emission control, the ECM uses a closed loop air/fuel metering system. The ECM monitors 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 trim value is around 0%. The ECM will add fuel when the HO2S signal is indicating a lean condition. Additional fuel is indicated by fuel trim values that are above 0%. The ECM 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 ECM 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 ECM sets DTC P2096 if either trim value or the difference of rear HO2S from desired value is reached to the maximum threshold.
If the same error code is set in the next driving cycle, the ECM illuminates the MIL.
DTC Detecting Condition:
Schematic Diagram:
Signal Waveform:
Monitor DTC Status
CAUTION: If any Three Way Catalyst (TWC) or O2 Sensor (B1/S2) codes are present, DO ALL REPAIRS associated with those codes before proceeding with this troubleshooting tree.
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode
2. Press F5 (INFO) to select DTC information from the DTCs menu
3. Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
4. Read "DTC Status" parameter
5. Is parameter displayed "History (Not Present) fault"?
CAUTION:
- History (Not Present) fault : DTC occurred but has been cleared.
- Present fault : DTC is occurring at present time.
YES
a. Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for loose or poor connections, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure
NO
a. Go to next step as below
Component Inspection
1. Visually/physically inspect the air leakage in exhaust system
2. Visually/physically inspect the TWC and HO2S (B1/S2) for contamination, deterioration, or damage.
3. Was a problem found in any of the above areas?
YES
a. Replace or repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
a. Go to next step as below
4. Warm up the engine to normal operating temperature and check that HO2S signal is active.
5. Connect Scantool and monitor the "O2 SNSR VOLT. (B1/S2)" parameter on the Scantool data list.
Test Condition : Ignition "ON" & Engine "ON" & In Idle ("Closed Loop")condition
6. Is sensor data near the specified value?
YES
a. Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
a. Check HO2S (B1/S2) for contamination, deterioration, or damage. Substitute with a known-good HO2S (B1/S2) and check for proper operation. If the problem is corrected, replace HO2S (B1/S2) and then go to "Verification of Vehicle Repair" procedure
Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected. Verification of Vehicle Repair
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode
2. Press F5 (INFO) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
3. Read "DTC Status" parameter
4. Is parameter displayed "History (Not Present) fault"?
YES
a. System performing to specification at this time. Clear the DTC
NO
a. Go to the applicable troubleshooting procedure.