P2097
DTC P2097
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
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 -20°C and +200°C (-4 and +392°F).
* The start up engine coolant temperature is warmer than -20°C (-4°F).
* The fuel control intrusive diagnostics are not active.
* The engine is operating under cruise conditions.
* DTC P2097 runs continuously when the conditions above have been met.
Conditions for Setting the DTC
The rich correction limit for a condition causing a lean air/fuel ratio has been exceeded.
Action Taken when the DTC Sets
* DTCs P2097 is a Type B DTC.
* 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 P2097 is a Type B DTC.
* 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
* It is very unlikely that an HO2S will cause this DTC to set without the occurrence of circuit related HO2S DTCs. Do not replace an HO2S to address this DTC without first performing all the steps in Circuit/System Verification and Circuit/System Testing.
* 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 [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References 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 Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
• If no other HO2S or fuel trim DTC is set
3. Verify DTC 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 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:
* Exhaust system leaks. Refer to Symptoms - Engine Exhaust 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. Refer to Crankcase Ventilation System Inspection/Diagnosis Testing and Inspection.
* Engine vacuum leaks
* Low fuel system pressure. Refer to Fuel System Diagnosis Fuel System Diagnosis.
* Contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis Testing and Inspection.
* Lean fuel injectors. Refer to Fuel Injector Diagnosis Fuel Injector Diagnosis.
If a condition is found
Repair as necessary.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.