PRE-RELEASE
DTC P2096 or P2097 (LLU)
| DTC P2096 or P2097 (LLU) |
| Diagnostic Instructions |
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Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
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| DTC Descriptors |
DTC P2096 00
Post Catalyst Fuel Trim System Low Limit
DTC P2097 00
Post Catalyst Fuel Trim System High Limit
| Diagnostic Fault Information |
| Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
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Signal Circuit
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P0131 00, P0137 00
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P0134 00, P0140 00
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P0132 00, P0138 00
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P0133 00, P2096 00, P2097 00
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Low Reference
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-
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P0134 00, P0140 00
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P0132 00, P0138 00
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P0133 00, P2096 00, P2097 00
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| Typical Scan Tool Data |
HO2S 1 or 2
| Circuit | Short to Ground | Open | Short to Voltage |
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Operating Conditions:
Engine operating in closed loop
Parameter Normal Range: 350-550 mV |
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Signal Circuit
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0 mV
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445-450 mV
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1275 mV
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Low Reference
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-
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445-480 mV
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1275 mV
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| Circuit/System Description |
The heated oxygen sensors (HO2S) 1 or 2 are used for fuel control and catalyst monitoring. Each heated oxygen sensor compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an open loop mode, ignoring the heated oxygen sensor signal voltage while calculating the air to fuel ratio. The control module supplies the heated oxygen sensor with a reference, or bias voltage of about 450 mV. While the engine runs, each heated oxygen sensor heats up and begins to generate a voltage within a range of 0-1000 mV. This voltage will fluctuate above and below the bias voltage. Once sufficient heated oxygen sensors 1 or 2 voltage fluctuation is observed by the control module, closed loop is entered. The control module uses the heated oxygen sensor voltage to determine the air to fuel ratio. An heated oxygen sensor voltage that increases above bias voltage toward 1000 mV indicates a rich fuel mixture. An heated oxygen sensor voltage that decreases below bias voltage toward 0 mV indicates a lean fuel mixture.
The heating elements inside each heated oxygen sensor heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter closed loop earlier and the control module to calculate the air to fuel ratio sooner.
| Conditions for Running the DTC |
P2096 00
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DTCs P0030 00, P0031 00, P0032 00, P0130 00, P0131 00, P0132 00, P0133 00, P0135 00, P0137 00, P0138 00, P0140 00, P2270 00, or P2271 00 are not set.
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The engine speed is between 1520-3520 RPM.
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The ignition voltage is between 10-18 V.
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The engine load is between 16-21%.
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Closed loop fuel control is active for greater than 5 s.
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The Evaporative Emission (EVAP) system is not purging.
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The calculated exhaust gas temperature is greater than 250°C (482°F)
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The DTC run continuously once the above conditions are met for 100 s.
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P2097 00
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DTCs P0030 00, P0031 00, P0032 00, P0130 00, P0131 00, P0132 00, P0133 00, P0135 00, P0137 00, P0138 00, P0140 00, P2270 00, or P2271 00 are not set.
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The engine speed is between 1520-3520 RPM.
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The ignition voltage is between 10-18 V.
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The engine load is between 17-20%.
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The EVAP system is not purging.
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Closed loop fuel control is active for greater than 5 s.
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The DTC run continuously once the above conditions are met for 100 s.
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| Conditions for Setting the DTC |
P2096 00
The long term fuel trim has reached its low limit while the HO2S voltage is still trying to move the adjustment further in the same direction.P2097 00
The long term fuel trim has reached its high limit while the HO2S voltage is still trying to move the adjustment further in the same direction.| Action Taken When the DTC Sets |
DTCs P2096 00, P2097 00 are Type B DTCs.
| Conditions for Clearing the DTC |
DTCs P2096 00, P2097 00 are Type B DTCs.
| Reference Information |
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
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Circuit Testing
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Connector Repairs
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Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs
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DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
| Circuit/System Verification |
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Ignition ON, observe the scan tool DTC information. Verify there is no other HO2S or fuel trim DTC set.
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| 2. |
If any DTC is set, refer to
Diagnostic Trouble Code (DTC) List - Vehicle
for further diagnosis.
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| 3. |
Refer to
Road Test Warning
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Allow the engine to reach operating temperature. |
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| 4. |
Drive the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you have noted from the freeze frame/failure records data.
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| Circuit/System Testing |
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All modules must be powered down or misdiagnosis may result. |
| 1. |
Verify none of the following conditions exist:
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Inspect the B52A Heated Oxygen Sensor 1 or B52B Heated Oxygen Sensor 2 for being secure
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Damaged wiring between either B52A Heated Oxygen Sensor 1 or B52B Heated Oxygen Sensor 2 and the ECM
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Water intrusion in the B52A Heated Oxygen Sensor 1 or B52B Heated Oxygen Sensor 2 harness connector
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Low or high fuel-system pressure. Refer to
Fuel System Description
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Fuel that is contaminated. Refer to
Alcohol/Contaminants-in-Fuel Diagnosis
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Fuel saturation of the evaporative emission (EVAP) canister
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Exhaust leaks near the B52A Heated Oxygen Sensor 1 or B52B Heated Oxygen Sensor 2
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Engine vacuum leaks
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If you find any of the above conditions, repair as necessary.
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| 2. |
Ignition OFF, disconnect the harness connector at the B52B Heated Oxygen Sensor 2.
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Ignition ON, verify the scan tool HO2S Sensor 2 voltage parameter is between 350-550 mV.
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If lower than the specified value, test the high signal circuit for the B52B heated oxygen sensor 2 for a short to ground. If the circuit/connections test normal, replace the K20 engine control module.
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Connect the harness connector at the B52B Heated Oxygen Sensor 2.
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Engine idling, increase the engine speed to over 1200 rpm for 30 seconds. Verify that the scan tool HO2S Sensor 2 voltage parameter is greater than 60 mV.
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If less than the specified range, replace the B52B Heated Oxygen Sensor 2.
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Engine idling, move the B52A Heated Oxygen Sensor 1 or B52B Heated Oxygen Sensor 2 harnesses between the HO2S harness connector and the K20 Engine Control Module. Observe the scan tool HO2S Sensor 1 and HO2S Sensor 2 voltage parameter. Verify neither parameter changes abruptly.
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If the parameter changes abruptly, repair the harness/connections as necessary.
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| 10. |
If all circuits test normal, replace the B52B Heated Oxygen Sensor 2.
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| Repair Instructions |
Refer to Heated Oxygen Sensor Resistance Learn Reset Caution .
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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Heated Oxygen Sensor Replacement - Sensor 2
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Control Module References
for ECM replacement, setup, and programming
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