SFI 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.

A019JLAE01
DTC No. DTC Detection Condition Trouble Area
P2195

Conditions (a) and (b) continue for 5 seconds or more

(2 trip detection logic):

(a) Air fuel ratio sensor voltage is higher than 3.8 V.

(b) Heated oxygen sensor voltage is 0.21 V or higher.


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

  • Air fuel ratio sensor (bank 1 sensor 1)

  • Intake system

  • Fuel pressure

  • Fuel injector assembly

  • ECM

While the fuel-cut operation is performed (during vehicle deceleration), the air fuel ratio sensor current is 2.2 mA or higher for 3 seconds (2 trip detection logic).
  • Air fuel ratio sensor (bank 1 sensor 1)

  • ECM

P2196

Conditions (a) and (b) continue for 5 seconds or more

(2 trip detection logic):

(a) Air fuel ratio sensor voltage is below 2.8 V.

(b) Heated oxygen sensor voltage is below 0.69 V.


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

  • Air fuel ratio sensor (bank 1 sensor 1)

  • Intake system

  • Fuel pressure

  • Fuel injector assembly

  • ECM

While the fuel-cut operation is performed (during vehicle deceleration), the air fuel ratio sensor current is below 0.7 mA for 3 seconds (2 trip detection logic).
  • Air fuel ratio sensor (bank 1 sensor 1)

  • ECM

Tech Tips


  • When any of these DTCs is stored, check the air fuel ratio sensor output voltage by entering the following menus: Powertrain / Engine / 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.

WIRING DIAGRAM

A019P6CE01

CONFIRMATION DRIVING PATTERN

This confirmation driving pattern is used in the "Perform Confirmation Driving Pattern" procedure of the following diagnostic troubleshooting procedure.

A019KK3E11
A019MZEE39

  1. Connect the intelligent tester to the DLC3.

  2. Turn the engine switch on (IG).

  3. Turn the tester on.

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

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

  6. Turn the engine switch on (IG) and turn the tester on.

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

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

  9. Drive the vehicle at a speed between 60 and 120 km/h (37 and 75 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 S [C], accelerate the vehicle to 64 km/h (40 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 1400 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 / DTC / Pending [F].

  15. Read the 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 / 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.

INSPECTION PROCEDURE

Tech Tips

Malfunctioning areas can be identified by performing the Control the Injection Volume function provided in the Active Test. The Control the Injection Volume function can help to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume operation using the intelligent tester.


  1. Connect the intelligent tester to the DLC3.

  2. Start the engine.

  3. Turn the tester on.

  4. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.

  5. Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume.

  6. Perform the Active Test operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).

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

Tech Tips


  • Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations.

  • Each sensor reacts in accordance with increases and decreases in the fuel injection volume.

Tester Display (Sensor) Injection Volume Status Voltage

AFS Voltage B1S1

(Air fuel ratio)

+12% Rich Below 3.1 V
-12% Lean Higher than 3.4 V

O2S B1S2

(Heated oxygen)

+12% Rich Higher than 0.55 V
-12% Lean Below 0.4 V

Note

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.

Case Air Fuel Ratio Sensor (Sensor 1) Output Voltage Heated Oxygen Sensor (Sensor 2) Output Voltage Main Suspected Trouble Area
1 A019L7QE05 A019OABE08 A019L7QE05 A019O5QE06 -
2 A019L7QE05 A019MDPE01 A019L7QE05 A019O5QE06
  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor circuit

3 A019L7QE05 A019OABE08 A019L7QE05 A019MDPE01
  • Heated oxygen sensor

  • Heated oxygen sensor heater

  • Heated oxygen sensor circuit

4 A019L7QE05 A019MDPE01 A019L7QE05 A019MDPE01
  • Fuel injector assembly

  • Fuel pressure

  • Gas leak from exhaust system (Air fuel ratio extremely rich or lean)


Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips


  • Although the DTC titles say oxygen sensor, these DTCs relate to the air fuel ratio sensor.

  • Sensor 1 refers to the sensor mounted in front of the Three-way Catalytic Converter (TWC) and located near the engine assembly.

  • 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.

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

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

  • Sensor 1 refers to the sensor closest to the engine assembly.

  • Sensor 2 refers to the sensor farthest away from the engine assembly.

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 engine switch on (IG).

    3. Turn the tester on.

    4. Enter the following menus: Powertrain / Engine / 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
    A
  2. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST


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


    NO
    YES
  3. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the engine switch off.

    6. Turn the engine switch on (IG) and turn the tester on.

    7. Start the engine and warm it up.

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

    9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

    10. Input the DTC: P2195 or P2196.

    11. Check the DTC judgment result.

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

    B
    A
  4. READ VALUE USING INTELLIGENT TESTER (AIR FUEL RATIO SENSOR CURRENT)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Enter the following menus: Powertrain / Engine / Data List / All Data / AFS Current B1S1.

    6. Check the value of the air fuel ratio sensor output current during fuel-cut, referring to the Monitor Drive Pattern Detail for Procedure "C" though Procedure "E" in the Confirmation Driving Pattern.

      Tech Tips


      • To measure the air fuel ratio sensor current precisely, perform the fuel-cut operation as long as possible.

      • If it is difficult to measure the sir fuel ratio sensor current, use the snapshot function of the tester.

      Result
      Result Proceed to
      Within normal range (0.7 mA or higher, and below 2.2 mA) A
      Outside normal range (Below 0.7 mA, or 2.2 mA or higher) B

    B
    A
  5. 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 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 / Active Test / Control the Injection Volume / All Data / AFS Voltage B1S1 and O2S B1S2.

    6. Perform the Control the Injection Volume 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 tester.

      Tech Tips


      • Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations.

      • 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.

      Tester Display (Sensor) Injection Volume Status Voltage

      AFS Voltage B1S1

      (Air fuel ratio)

      +12% Rich Less than 3.1 V

      AFS Voltage B1S1

      (Air fuel ratio)

      -12% Lean More than 3.4 V

      O2S B1S2

      (Heated oxygen)

      +12% Rich More than 0.55 V

      O2S B1S2

      (Heated oxygen)

      -12% Lean Less than 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 C

      Lean: During the Control the Injection Volume Active Test, the air fuel ratio sensor output voltage (AFS Voltage B1S1) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S B1S2) is consistently below 0.4 V.

      Rich: During the Control the Injection Volume 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 Active Test, the output voltage of the air fuel ratio sensor and heated oxygen sensor alternates correctly.

      Tech Tips

      Refer to "Data List / Active Test" [AFS Voltage B1S1, O2S B1S2] Click here.


    B
    C
    A
  6. CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leaks Click here.

      OK
      No leaks in intake system.

    NG
    OK
  7. CHECK FOR EXHAUST GAS LEAK


    1. Check for exhaust gas leaks.

      OK
      No gas leaks.

    NG
    OK
  8. CHECK FUEL PRESSURE


    1. Check the fuel pressure Click here.


    NG
    OK
  9. 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
    OK
  10. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT
  11. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the engine switch off.

    6. Turn the engine switch on (IG) and turn the tester on.

    7. Start the engine and warm it up.

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

    9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

    10. Input the DTC: P2195 or P2196.

    11. Check the DTC judgment result.

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

    B
    A
  12. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT
  13. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Clear the DTC Click here.

    5. Turn the engine switch off.

    6. Turn the engine switch on (IG) and turn the tester on.

    7. Start the engine and warm it up.

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

    9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

    10. Input the DTC: P2195 or P2196.

    11. Check the DTC judgment result.

      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


    NEXT
  14. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT
  15. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the engine switch off.

    6. Turn the engine switch on (IG) and turn the tester on.

    7. Start the engine and warm it up.

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

    9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

    10. Input the DTC: P2195 or P2196.

    11. Check the DTC judgment result.

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

    B
    A
  16. CHECK FUEL LINE


    1. Check the fuel lines for leaks or blockage.


    NG
    OK