Chevrolet Trax: DTC P2096 OR P2097

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 Descriptor

DTC P2096

Post Catalyst Fuel Trim System Low Limit

DTC P2097

Post Catalyst Fuel Trim System High Limit

Circuit Description

Fuel trim bias is used to keep the post catalyst air/fuel ratio within a predetermined range. This allows optimal catalyst efficiency under various operating conditions. The engine control module (ECM) constantly monitors how lean or rich the fuel trim bias is commanded, to determine if the fuel trim bias is greater than a calibrated amount.

Conditions for Running the DTC

• DTC P0016, P0017, P0030, P0036, P0053, P0054, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P013A, P013B, P013E, P013F, P0140, P0141, P015A, P015B, P0201, P0202, P0203, P0204, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0300, P0301, P0302, P0303, P0304, P0340, P0341, P0365, P0366, P0411, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P1248, P1249, P124A, P124B, P2147, P2148, P2150, P2151, P2153, P2154, P2156, P2157, P219A, P2227, P2228, P2229, P2230, P2270, P2271, P2440, or P2444 is not set.
• The barometric pressure (BARO) is greater than 70 kPa (10.2 PSI).
• The manifold absolute pressure (MAP) is between 0-200 kPa (0-29 PSI).
• The intake air temperature (IAT) is between -20ºC and +50ºC (-4 and +122ºF).
• The start up engine coolant temperature is warmer than -20ºC (-4ºF).
• The fuel control intrusive diagnostics are not active.
• The engine is operating under cruise, light acceleration, or heavy acceleration.
• DTCs P2096 and P2097 run continuously when the conditions above have been met.

Conditions for Setting the DTC

The correction limit for a condition causing a lean or rich air/fuel ratio has been exceeded.

Action Taken when the DTC Sets

• DTCs P2096 and P2097 are Type B DTCs.
• The ECM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the ECM stores this information in the Failure records. If the diagnostic reports a failure on the second ignition cycle, the ECM records the operating conditions at the time of the failure. The ECM writes the operating conditions to the Freeze Frame and updates the Failure records. The ECM illuminates the malfunction indicator lamp (MIL) when one of the following occurs:

• The ECM detects the same fuel trim failure during 2 consecutive trips.
• The ECM detects any fuel trim failure during any subsequent trip if the conditions at the time of failure meet the following criteria:

• The engine load is within 20 percent of the previous test that failed.
• The engine speed is within 375 RPM of the previous test that failed.
• The engine coolant temperature is in the same range of the previous test that failed.

Conditions for Clearing the MIL/DTC

• DTCs P2096 and P2097 are Type B DTCs.
• The ECM turns OFF the malfunction indicator lamp (MIL) at the beginning of the fourth ignition cycle, after 3 ignition cycles that the diagnostic runs and does not fail.
• A current DTC, Last Test Failed, clears when the diagnostic runs and passes.

Diagnostic Aids

• The post catalyst fuel trim diagnostic is very sensitive to heated oxygen sensor (HO2S) design. A non-OE sensor or an incorrect part number may cause a DTC to set.
• Certain aftermarket air filters may cause a DTC to set.
• Certain aftermarket air induction systems or modifications to the air induction system may cause a DTC to set.
• Certain aftermarket exhaust system components may cause a DTC to set.

Reference Information

Schematic Reference

Engine Controls Schematics (Encore) , Engine Controls Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Component View Reference

Powertrain Component 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 (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.
2. Verify no other HO2S or fuel trim DTC is set.

• If any other HO2S or fuel trim DTC is set

Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

• If no other HO2S or fuel trim DTC is set

3. Verify DTC P2096 or P2097 is not set.

• If a DTC is set

Refer to Circuit/System Testing.

• If no DTC is set

4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed in the Freeze Frame/Failure Records data.
5. Verify DTC P2096 or P2097 is not set.

• If a DTC is set

Refer to Circuit/System Testing.

• If no DTC is set

6. All OK.

Circuit/System Testing

Verify none of the conditions listed below exist:

P2096

• Air intake duct collapsed or restricted.
• Air filter dirty or restricted.
• Objects blocking the throttle body.
• Excessive fuel in the crankcase. Change engine oil as necessary.
• Rich fuel injectors. Refer to Fuel Injector Diagnosis.
• Excessive fuel system pressure. Refer to Fuel System Diagnosis (LUJ), Fuel System Diagnosis (LUV).
• Fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis.
• Fuel saturation of the evaporative emissions (EVAP) canister
• Stuck open or leaking EVAP purge valve
• Restricted exhaust. Refer to Symptoms - Engine Exhaust .
• Improper operation of the crankcase ventilation system.

P2097

• Exhaust system leaks. Refer to Symptoms - Engine Exhaust .
• Vacuum hoses for splits, kinks, and proper connections
• Insufficient fuel in the tank
• Air induction system and air intake ducts for leaks
• Missing air filter element
• Cracked evaporative canister
• Evaporative pipes plugged, obstructed, or leaking
• Crankcase ventilation system leaking.
• Engine vacuum leaks
• Low fuel system pressure. Refer to Fuel System Diagnosis (LUJ), Fuel System Diagnosis (LUV).
• Contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis.
• Lean fuel injectors. Refer to Fuel Injector Diagnosis
• If a condition is found

Repair as necessary.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Reset the fuel trim after completing the repair.

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