SFI SYSTEM (w/ Secondary Air Injection System), Diagnostic DTC:P2195, P2196

DTC Code DTC Name
P2195 Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)
P2196 Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1 Sensor 1)

DESCRIPTION

The air fuel ratio sensor generates a voltage* that corresponds to the actual air-fuel ratio. This sensor voltage is used to provide the ECM with feedback so that it can control the air-fuel ratio. The ECM determines the deviation from the stoichiometric air-fuel ratio and regulates the fuel injection time. If the air fuel ratio sensor malfunctions, the ECM is unable to control the air-fuel ratio accurately.

The air fuel ratio sensor is of the planar type and is integrated with a heater, which heats the solid electrolyte (zirconia element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust gas temperature is low), a current flows through the heater to heat the sensor in order to facilitate accurate air-fuel ratio detection. In addition, the sensor and heater portions are the narrow type. The heat generated by the heater is conducted to the solid electrolyte through the alumina, thereby accelerating the sensor activation.

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a Three-Way Catalytic Converter (TWC) is used. For the most efficient use of the Three-Way Catalytic Converter (TWC), the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric level.

*: The value changes inside the ECM. Since the air fuel ratio sensor is a current output element, the current is converted into a voltage inside the ECM. Any measurements taken at the air fuel ratio sensor or ECM connectors will show a constant voltage.

B007RA2E01
DTC No. DTC Detection Condition Trouble Area
P2195

Conditions (a) and (b) continue for 10 seconds or more (2 trip detection logic)


  • (a) Air fuel ratio sensor voltage more than 3.8 V

  • (b) Heated oxygen sensor voltage is 0.15 V or more

  • Open or short in air fuel ratio sensor (Sensor 1) circuit

  • Air fuel ratio sensor (Sensor 1)

  • Air fuel ratio sensor (Sensor 1) heater

  • Air induction system

  • Exhaust system

  • Fuel line

  • Fuel pressure

  • Fuel injector assembly

  • ECM
While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is 3.6 mA or more for 3 seconds (2 trip detection logic)

  • Air fuel ratio sensor (Sensor 1)

  • ECM
P2196

Conditions (a) and (b) continue for 10 seconds or more (2 trip detection logic)


  • (a) Air fuel ratio sensor voltage less than 2.8 V

  • (b) Heated oxygen sensor voltage is below 0.60 V

  • Open or short in air fuel ratio sensor (Sensor 1) circuit

  • Air fuel ratio sensor (Sensor 1)

  • Air fuel ratio sensor (Sensor 1) heater

  • Air induction system

  • Exhaust system

  • Fuel line

  • Fuel pressure

  • Fuel injector assembly

  • ECM
While fuel-cut operation performed (during vehicle deceleration), air fuel ratio sensor current is less than 1.0 mA for 3 seconds (2 trip detection logic)

  • Air fuel ratio sensor (Sensor 1)

  • ECM

Tech Tips


  • When either of these DTCs is stored, check the air fuel ratio sensor output voltage by entering the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Voltage B1S1.

  • Short-term fuel trim values can also be read using the intelligent tester.

  • The ECM maintains the voltages at the A1A+ and A1A- terminals of the ECM at a constant level. Therefore, the air fuel ratio sensor output voltage cannot be confirmed without using the intelligent tester.

  • If the air fuel ratio sensor is malfunctioning, the ECM stores DTC P2195 or P2196.

MONITOR DESCRIPTION

Sensor voltage detection monitor

Under air-fuel ratio feedback control, If the air fuel ratio sensor output voltage is below 2.8 V (very rich condition) for 10 seconds despite the rear heated oxygen sensor output voltage being below 0.60 V, the ECM stores DTC P2196. Alternatively, if the air fuel ratio sensor output voltage is higher than 3.8 V (very lean condition) for 10 seconds despite the rear heated oxygen sensor output voltage being 0.15 V or higher, DTC P2195 is stored.

Sensor current detection monitor

A rich air-fuel mixture causes a low air fuel ratio sensor current, and a lean air-fuel mixture causes a high air fuel ratio sensor current. Therefore, the sensor output becomes low during acceleration, and it becomes high during deceleration with the throttle valve fully closed. The ECM monitors the air fuel ratio sensor current during fuel-cut and detects any abnormal current values.

If the air fuel ratio sensor output is 3.6 mA or higher for more than 3 seconds of cumulative time, the ECM interprets this as a malfunction in the air fuel ratio sensor and stores DTC P2195 (stuck on high side). If the air fuel ratio sensor output is below 1.0 mA for more than 3 seconds of cumulative time, the ECM stores DTC P2196 (stuck on low side).

B007W6IE38

CONFIRMATION DRIVING PATTERN

B007V7FE82
B007VJJE02

  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON.

  3. Turn the tester on.

  4. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

  5. Turn the ignition switch off and wait for at least 30 seconds.

  6. Turn the ignition switch to ON and turn the tester on.

  7. Start the engine and warm it up until the ECT reaches 75°C (167°F) or higher [A].

  8. On the tester, enter the following menus to check the fuel-cut status: Powertrain / Engine and ECT / Data List / Idle Fuel Cut.

  9. Drive the vehicle at a speed between 60 and 100 km/h (37 and 63 mph) for at least 10 minutes [B].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

  10. With the shift lever in 2nd gear (for M/T) or 2nd range (for A/T) [C], accelerate the vehicle to 60 km/h (37 mph) or more by depressing the accelerator pedal for at least 10 seconds [D].

    CAUTION:

    When performing the confirmation driving pattern, obey all speed limits and traffic laws.

  11. Soon after performing step [D] above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal in order to execute fuel-cut control [E].

    Tech Tips

    Fuel-cut is performed when the following conditions are met:


    • Accelerator pedal is fully released.

    • Engine speed is 2500 rpm or more (fuel injection returns at 1000 rpm).

  12. Allow the vehicle to decelerate until the vehicle speed decreases to less than 10 km/h (6 mph).

  13. Repeat steps [C] through [E] above at least 3 times in one driving cycle.

  14. Enter the following menus: Powertrain / Engine and ECT / DTC [F].

  15. Read pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  16. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  17. Input the DTC: P2195 or P2196.

  18. Check the DTC judgment result.

    Tester Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or N/A, perform steps [B] through [F] again.

WIRING DIAGRAM

Refer to DTC P0031 Click here.

INSPECTION PROCEDURE

Tech Tips


  • DTC P2A00 may be set, when the air-fuel ratio is stuck rich or lean.

  • A low A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that would cause the engine to run rich.

  • A high A/F sensor voltage could be caused by a lean air-fuel mixture. Check for conditions that would cause the engine to run lean.

  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / DTC.

    5. Read the DTCs.

      Result
      Result Proceed to
      P2195 or P2196 is output A
      P2195 or P2196 and P0136, P0137 or P0138 are output A
      P2195 or P2196 and other DTCs are output B

      Tech Tips

      If any DTCs relating to the air fuel ratio sensor (DTCs for the air fuel ratio sensor heater or air fuel ratio sensor admittance) are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST


    1. Has the vehicle run out of fuel in the past?


    NO

    READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR) Click here

    YES

  3. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTCs Click here.

    5. Turn the ignition switch off and wait for at least 30 seconds.

    6. Start the engine and warm it up.

    7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    8. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    9. Input the DTC: P2195 or P2196.

    10. Check the DTC judgment result.

      Result
      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P2195 or P2196 is output) B

    B

    READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR) Click here

    A

    DTC CAUSED BY RUNNING OUT OF FUEL

  4. READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF AIR FUEL RATIO SENSOR)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine.

    3. Turn the intelligent tester on.

    4. Warm up the air fuel ratio sensor at an engine speed of 2500 rpm for 90 seconds.

    5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.

    6. Perform the Control the Injection Volume for A/F Sensor operation with the engine idling.

    7. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the intelligent tester.

      Tech Tips


      • Change the fuel injection volume within the range of -12.5% to +12.5%.

      • The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.

      • If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

      Intelligent tester Display (Sensor) Injection Volume Status Voltage

      AFS Voltage B1S1

      (Air fuel ratio)

      		 +12.5% Rich Below 3.1 V

      AFS Voltage B1S1

      (Air fuel ratio)

      		 -12.5% Lean Higher than 3.4 V

      O2S B1S2

      (Heated oxygen)

      		 +12.5% Rich Higher than 0.55 V

      O2S B1S2

      (Heated oxygen)

      		 -12.5% Lean Below 0.4 V
      Result
      Status of AFS Voltage B1S1 Status of O2S B1S2 Air Fuel Ratio Condition and Air Fuel Ratio Sensor Condition Proceed to
      Lean Lean Actual air fuel ratio lean A
      Rich Rich Actual air fuel ratio rich A
      Lean Lean/Rich Air fuel ratio sensor malfunction B
      Rich Lean/Rich Air fuel ratio sensor malfunction B
      Lean/Rich Lean/Rich Normal B

      Lean: During the Control the Injection Volume for A/F Sensor Active Test, the air fuel ratio sensor output voltage (AFS Voltage) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S) is consistently below 0.4 V.

      Rich: During the Control the Injection Volume for A/F Sensor Active Test, the AFS Voltage is consistently below 3.1 V, and the O2S is consistently higher than 0.55 V.

      Lean/Rich: During the Control the Injection Volume for A/F Sensor Active Test, the output voltage of the heated oxygen sensor alternates correctly.


    B

    REPLACE AIR FUEL RATIO SENSOR Click here

    A

  5. CHECK FOR AIR INDUCTION SYSTEM


    1. Check the air induction system for vacuum leaks.

      OK
      No leaks in air induction system.

    NG

    REPAIR OR REPLACE AIR INDUCTION SYSTEM

    OK

  6. CHECK FOR EXHAUST GAS LEAK


    1. Check for exhaust gas leaks.

      OK
      No gas leaks.

    NG

    REPAIR OR REPLACE EXHAUST SYSTEM

    OK

  7. CHECK FUEL PRESSURE


    1. Check the fuel pressure Click here.


    NG

    CHECK FUEL LINE Click here

    OK

  8. INSPECT FUEL INJECTOR ASSEMBLY


    1. Check the fuel injector assembly (whether fuel volume is high or low, and whether injector pattern is poor) Click here.


    NG

    REPLACE FUEL INJECTOR ASSEMBLY Click here

    OK

  9. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT

  10. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTCs Click here.

    5. Turn the ignition switch off and wait for at least 30 seconds.

    6. Start the engine and warm it up.

    7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    8. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    9. Input the DTC: P2195 or P2196.

    10. Check the DTC judgment result.

      Result
      Result Proceed to
      ABNORMAL (DTC P2195 or P2196 is output) A
      NORMAL (DTC is not output) B

    B

    END

    A

  11. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  12. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTC Click here.

    5. Turn the ignition switch off and wait for at least 30 seconds.

    6. Start the engine and warm it up.

    7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    8. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    9. Input the DTC: P2195 or P2196.

    10. Check the DTC judgment result.

      Result
      Intelligent tester Display Description
      NORMAL

      • DTC judgment completed

      • System normal
      ABNORMAL

      • DTC judgment completed

      • System abnormal
      INCOMPLETE

      • DTC judgment not completed

      • Perform driving pattern after confirming DTC enabling conditions
      N/A

      • Unable to perform DTC judgment

      • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    NEXT

    END

  13. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT

  14. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Clear the DTCs Click here.

    5. Turn the ignition switch off and wait for at least 30 seconds.

    6. Start the engine and warm it up.

    7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

    8. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

    9. Input the DTC: P2195 or P2196.

    10. Check the DTC judgment result.

      Result
      Result Proceed to
      NORMAL (DTC is not output) A
      ABNORMAL (DTC P2195 or P2196 is output) B

    B

    REPLACE ECM Click here

    A

    END

  15. CHECK FUEL LINE


    1. Check the fuel lines for leaks or blockage.


    NG

    REPAIR OR REPLACE FUEL LINE

    OK

    REPLACE FUEL PUMP Click here