P2096
DTC P2096: Post Catalyst Fuel Trim System Low Limit Bank 1Wiring Diagram:
Circuit Description
The Engine Control Module (ECM) supplies a voltage of about 0.45 V to the oxygen sensor. The Oxygen Sensor (O2S) varies the voltage within a range of about 1 V if the exhaust is rich, down to about 0.1 V if the exhaust is lean. This diagnosis can detect the sluggish behavior of the lean shift of HO2S1 and detect the abnormality of HO2S2 (below 0.65 V). A malfunction is registered if the fuel trim control values exceed the maximum threshold value for the diagnosis time during fuel trim control activation phase. If catalysts are deteriorated, HO2S2 signal oscillates according to the actual lambda signal. So, the diagnosis must be considered with catalyst deterioration factor.
Conditions for Setting the DTC
Fuel trim values reached limit and one of the emission values in the FTP test is exceeded.
Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate.
- The ECM will record operating conditions at the time the diagnostic fail. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.
Conditions for Clearing the MIL/DTC
- The MIL will turn OFF at the end of 3 consecutive validation cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 warm up cycles without a fault.
- DTC(s) can be cleared by using the scan tool.
Diagnostic Aids
An intermittent malfunction may be caused by a problem in the HO2S electrical circuit. Inspect the wiring harness and the components for an intermittent condition. Refer to Intermittents. Intermittents
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
2. This step determines if a condition exists.
4. This step is testing for a rear HO2S circuit condition. A circuit condition sets this DTC.
7. This step inspects for the rear sensors being connected to the correct bank of the engine. This condition causes this DTC to set.
8. This step is testing for an intermittent circuit condition. Thoroughly inspect the HO2S circuits for an intermittent circuit condition.
9. This step is testing for an intermittent circuit condition. Thoroughly inspect the HO2S circuits for an intermittent circuit condition.
Step 1 - 3:
Step 3 (Continued) - 12:
Step 13 - 20:
DTC Troubleshooting