P2097
DTC P2097 or P2099
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC P2097
- Post Catalyst Fuel Trim System High Limit Bank 1
DTC P2099
- Post Catalyst Fuel Trim System High Limit Bank 2
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 light load conditions at a steady cruise. 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
Condition 1
* Before the ECM can report DTC P2097 or P2099 failed, DTCs P0036, P0037, P0038, P0056, P0057, P0058, P0130, P0137, P0138, P0140, P0150, P0157, P0158, P0160, P064D, P064E, P2231, P2232, P2234, P2235, P2270, P2271, P2272, P2273, P2297, and P2298, must run and pass.
* DTC P0030, P0031, P0032, P0050, P0051, P0052, P0131, P0132, P0135, P0141, P0151, P0152, P0155, P0161, P2237, P2240, P2243, P2247, P2251, P2254, P2626, or P2629 is not set.
* The engine is operating.
* The engine speed and load are steady.
* The Closed Loop fuel control is active.
* The engine has cycled ON and OFF greater than 29 times.
* The fuel system is not in decel fuel cut-off (DEFCO)
* Catalyst heating or catalyst clear-out is not active.
* The cumulative mass air flow (MAF) into the engine is greater than 150 grams.
* The MAF is between 6-39 g/s
* The calculated exhaust temperature is between 350-850°C (662-1,562°F).
* The HO2S 1 Lambda is less than 1.000.
* HO2S 2 signal voltage is greater than 400 mV.
* DTCs P2097 and P2099 run continuously when the conditions above have been met.
Condition 2
* Before the ECM can report DTC P2097 or P2099 failed, DTCs P0036, P0037, P0038, P0056, P0057, P0058, P0130, P0137, P0138, P0140, P0150, P0157, P0158, P0160, P064D, P064E, P2231, P2232, P2234, P2235, P2270, P2271, P2272, P2273, P2297, and P2298, must run and pass.
* DTC P0030, P0031, P0032, P0050, P0051, P0052, P0131, P0132, P0135, P0141, P0151, P0152, P0155, P0161, P2237, P2240, P2243, P2247, P2251, P2254, P2626, or P2629 is not set.
* The HO2S 1 are in Closed Loop.
* The air flow into the engine is greater than 40 grams in each of a total of 7 auto-starts.
* The calculated exhaust gas temperature of the HO2S 1 is warmer than 720°C (1,328°F).
* The HO2S 1 Lambda is greater than 1.000.
* The HO2S 2 signal is greater than 600 mV.
* DTCs P2097 and P2099 run 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 for greater than 4 seconds.
Action Taken when the DTC Sets
DTCs P2097 and P2099 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P2097 and P2099 are Type B DTCs.
Diagnostic Aids
* An HO2S will not cause this DTC to set without also setting a circuit related DTC. Do not replace an HO2S to correct this DTC.
* An exhaust system leak that may not be audible can set this DTC.
Reference Information
Schematic Reference
Engine Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) 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.
• If any other HO2S or fuel trim DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions).
2. Verify that none of the following conditions exist:
* Exhaust system leaks-Refer to Exhaust Leakage (Exhaust Leakage)
* Engine vacuum leaks
* Low fuel system pressure-Refer to Fuel System Diagnosis (Fuel System Diagnosis)
* Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool) (Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool))Alcohol/Contaminants-in-Fuel Diagnosis (without Special Tool) (Alcohol/Contaminants-in-Fuel Diagnosis (without Special Tool))
* Lean fuel injectors-Refer to Fuel Injector Solenoid Coil Test (Fuel Injector Solenoid Coil Test)
• If you find any of the above conditions, repair as necessary.
Warning: Refer to Road Test Warning (Road Test Warning).
Note: A road load condition is necessary to obtain closed loop.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.