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DTC P2096 or P2097 (LLU)

DTC P2096 or P2097 (LLU)

Diagnostic Instructions


Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Review Strategy Based Diagnosis for an overview of the diagnostic approach.

Diagnostic Procedure Instructions provides an overview of each diagnostic category.


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
Signal Circuit

P0131 00, P0137 00

P0134 00, P0140 00

P0132 00, P0138 00

P0133 00, P2096 00, P2097 00

Low Reference

-

P0134 00, P0140 00

P0132 00, P0138 00

P0133 00, P2096 00, P2097 00



Typical Scan Tool Data

HO2S 1 or 2

Circuit Short to Ground Open Short to Voltage
Operating Conditions: Engine operating in closed loop

Parameter Normal Range: 350-550 mV

Signal Circuit

0 mV

445-450 mV

1275 mV

Low Reference

-

445-480 mV

1275 mV



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

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.

The engine speed is between 1520-3520 RPM.

The ignition voltage is between 10-18 V.

The engine load is between 16-21%.

Closed loop fuel control is active for greater than 5 s.

The Evaporative Emission (EVAP) system is not purging.

The calculated exhaust gas temperature is greater than 250°C (482°F)

The DTC run continuously once the above conditions are met for 100 s.



P2097 00

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.

The engine speed is between 1520-3520 RPM.

The ignition voltage is between 10-18 V.

The engine load is between 17-20%.

The EVAP system is not purging.

Closed loop fuel control is active for greater than 5 s.

The DTC run continuously once the above conditions are met for 100 s.


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


Circuit Testing

Connector Repairs

Testing for Intermittent Conditions and Poor Connections

Wiring Repairs


DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification


1. Ignition ON, observe the scan tool DTC information. Verify there is no other HO2S or fuel trim DTC set.

2. If any DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

3. Refer to Road Test Warning .

Note

The B52B Heated Oxygen Sensor 2 must be in closed loop for this diagnostic to run. A road load condition is necessary to obtain closed loop.


Allow the engine to reach operating temperature.

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.


Circuit/System Testing

Note

All modules must be powered down or misdiagnosis may result.



1. Verify none of the following conditions exist:

Inspect the B52A Heated Oxygen Sensor 1 or B52B Heated Oxygen Sensor 2 for being secure

Damaged wiring between either B52A Heated Oxygen Sensor 1 or B52B Heated Oxygen Sensor 2 and the ECM

Water intrusion in the B52A Heated Oxygen Sensor 1 or B52B Heated Oxygen Sensor 2 harness connector

Low or high fuel-system pressure. Refer to Fuel System Description .

Fuel that is contaminated. Refer to Alcohol/Contaminants-in-Fuel Diagnosis

Fuel saturation of the evaporative emission (EVAP) canister

Exhaust leaks near the B52A Heated Oxygen Sensor 1 or B52B Heated Oxygen Sensor 2

Engine vacuum leaks

If you find any of the above conditions, repair as necessary.

2. Ignition OFF, disconnect the harness connector at the B52B Heated Oxygen Sensor 2.

3. Ignition ON, verify the scan tool HO2S Sensor 2 voltage parameter is between 350-550 mV.

4. 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.

5. Connect the harness connector at the B52B Heated Oxygen Sensor 2.

6. 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.

7. If less than the specified range, replace the B52B Heated Oxygen Sensor 2.

8. 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.

9. If the parameter changes abruptly, repair the harness/connections as necessary.

10. If all circuits test normal, replace the B52B Heated Oxygen Sensor 2.


Repair Instructions

Refer to Heated Oxygen Sensor Resistance Learn Reset Caution .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


Heated Oxygen Sensor Replacement - Sensor 2

Control Module References for ECM replacement, setup, and programming