SFI SYSTEM(w/ EGR 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 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 level, and regulates the fuel injection duration. If the air fuel ratio sensor malfunctions, the ECM is unable to control the air fuel ratio accurately.

The air fuel ratio sensor is a planar type with an integrated 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), current flows to the heater to heat the sensor, in order to facilitate accurate oxygen concentration detection. In addition, the sensor and heater portions are narrower than the conventional type. The heat generated by the heater is conducted to the solid electrolyte through the alumina, therefore the sensor activation is accelerated.

A three-way catalytic converter is used in order to convert the carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxide (NOx) into less harmful substances. To allow the three-way catalytic converter to function effectively, it is necessary to keep the air fuel ratio of the engine near the stoichiometric air fuel ratio.

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

B001KT3E01
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 (sensor 1) circuit

  • Air fuel ratio sensor (sensor 1)

  • Intake system

  • Fuel pressure

  • Fuel injector assembly

  • EGR valve 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 (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 0.59 V.

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

  • Air fuel ratio sensor (sensor 1)

  • Intake system

  • Fuel pressure

  • Fuel injector assembly

  • EGR valve 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 (sensor 1)

  • ECM

Tech Tips


  • When any of these DTCs are set, 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 regulates the voltages at the A1A+ and A1A- terminals of the ECM to a constant level. Therefore, the air fuel ratio sensor output voltage cannot be confirmed without using the intelligent tester.

  • If an air fuel ratio sensor malfunction is detected, the ECM sets a DTC.

MONITOR DESCRIPTION



B001L4HE95

MONITOR STRATEGY

Required Sensors/Components (Main) Air fuel ratio sensor
Required Sensors/Components (Related) Heated oxygen sensor
Frequency of Operation

Continuous: Sensor voltage detection monitor

Once per driving cycle: Sensor current detection monitor
Duration

3 seconds: Sensor current detection monitor

5 seconds: Sensor voltage detection monitor

TYPICAL ENABLING CONDITIONS

Sensor Voltage Detection Monitor
Time after engine start 30 seconds or more
Air fuel ratio sensor status Activated
Fuel system status Closed-loop
Sensor Current Detection Monitor
Auxiliary battery voltage 11 V or higher
Engine coolant temperature 75°C (167°F) or higher
Atmospheric pressure 76 kPa (570 mmHg) or higher
Air fuel ratio sensor status Activated
Continuous time of fuel cut 3 to 10 seconds

TYPICAL MALFUNCTION THRESHOLDS

Sensor Voltage Detection Monitor (Lean Side Malfunction P2195)
Rear heated oxygen sensor voltage 0.21 V or higher
Air fuel ratio sensor voltage Higher than 3.8 V
Sensor Voltage Detection Monitor (Rich Side Malfunction P2196)
Rear heated oxygen sensor voltage Below 0.59 V
Air fuel ratio sensor voltage Below 2.8 V
Sensor Current Detection Monitor (High Side Malfunction P2195)
Air fuel ratio sensor current 2.2 mA or higher
Sensor Current Detection Monitor (Low Side Malfunction P2196)
Air fuel ratio sensor current Below 0.7 mA

CONFIRMATION DRIVING PATTERN

Tech Tips

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

B001LSKE02
B001KMQE09

  1. Connect the intelligent tester to the DLC3.

  2. Turn the power switch on (IG).

  3. Turn the tester on.

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

  5. Turn the power switch off and wait for 30 seconds.

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

  7. Put the engine in inspection mode (maintenance mode) Click here.

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

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

  10. Drive the vehicle at between 75 and 120 km/h (47 and 75 mph) for at least 10 minutes [B].

    CAUTION:

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

  11. Move the shift lever in B [C].

  12. Accelerate the vehicle to 75 km/h (47 mph) or more by depressing the accelerator pedal for at least 10 seconds [D].

  13. 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 control is executed when the accelerator pedal is released while the vehicle is moving at 35 km/h (22 mph) or slower (Fuel-cut control is prohibited when the engine sped decreases to 1000 rpm or lower).

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

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

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

  17. 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.

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

  19. Input the DTC: P2195 or P2196.

  20. 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 [E].

WIRING DIAGRAM

B001MVME02

CAUTION / NOTICE / HINT

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 and located near the engine assembly.

  • Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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 ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195 OR P2196)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

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

    5. Read the DTCs.

      Result
      Result Proceed to
      DTC P2195 or P2196 is output A
      "P2195 or P2196" and "P0136, P0137 or P0138" are output A
      DTC 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 (AIR FUEL RATIO SENSOR CURRENT) Click here

    YES

  3. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the power switch off and wait for 30 seconds.

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

    7. Put the engine in inspection mode (maintenance mode) Click here.

    8. Start the engine and warm it up.

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

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

    11. Input the DTC: P2195 or P2196.

    12. Check the DTC judgment result.

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

    A

    DTC CAUSED BY RUNNING OUT OF FUEL

    B

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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Put the engine in inspection mode (maintenance mode) Click here.

    6. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / AFS Current B1S1.

    7. Check the value of the air fuel ratio sensor output current during fuel-cut, referring to the Drive Pattern Detail for [C] through [F] 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 air fuel ratio sensor current, use the snapshot function of the tester.

      Result
      Test Value 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

    REPLACE AIR FUEL RATIO SENSOR NO.2 Click here

    A

  5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE INJECTION VOLUME)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Put the engine in inspection mode (maintenance mode) Click here.

    5. Start the engine.

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

    7. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume.

    8. Perform the Control the Injection Volume operation with the engine idling.

    9. 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 -12.0% to +12.0%. 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.

      Standard
      Tester Display (Sensor) Injection Volume Status Voltage

      AFS Voltage B1S1

      (Air fuel ratio)

      		 +12.0% Rich Below 3.1 V

      AFS Voltage B1S1

      (Air fuel ratio)

      		 -12.0% Lean Higher than 3.4 V

      O2S B1S2

      (Heated oxygen)

      		 +12.0% Rich Higher than 0.55 V

      O2S B1S2

      (Heated oxygen)

      		 -12.0% 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 C

      Lean: During the Control the Injection Volume 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 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 heated oxygen sensor alternates correctly.

      Tech Tips

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


    B

    REPLACE AIR FUEL RATIO SENSOR NO.2 Click here

    C

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  6. CHECK INTAKE SYSTEM


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

      OK
      No leaks in intake system.

    NG

    REPAIR OR REPLACE INTAKE SYSTEM

    OK

  7. CHECK FOR EXHAUST GAS LEAK


    1. Check for exhaust gas leaks from exhaust manifold sub-assembly and exhaust pipes..

      OK
      No gas leaks.

    NG

    REPAIR OR REPLACE EXHAUST SYSTEM

    OK

  8. CHECK FUEL PRESSURE


    1. Check the fuel pressure Click here.


    NG

    CHECK FUEL LINE Click here

    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

    REPLACE FUEL INJECTOR ASSEMBLY Click here

    OK

  10. REPLACE AIR FUEL RATIO SENSOR NO.2


    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 power switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the power switch off and wait for 30 seconds.

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

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

    8. Input the DTC: P2195 or P2196.

    9. 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

  12. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (CONTROL THE EGR STEP POSITION)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Put the engine in inspection mode (maintenance mode) Click here.

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

      Tech Tips

      The A/C switch and all accessory switches should be off.

    6. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position / Data List / All Data / Throttle Idle Position and MAP.

    7. Confirm that the Throttle Idle Position is ON and check the MAP value in the Data List while performing the Active Test.

      Tech Tips


      • Do not leave the EGR valve open for 10 seconds or more during the Active Test.

      • Be sure to return the EGR valve to step 0 when the Active Test is completed.

      • Do not open the EGR valve 30 steps or more during the Active Test.

      OK
      MAP change in response to EGR step position when Throttle Idle Position is ON in Data List.
      Standard
      - EGR Step Position (Active Test)
      0 Steps 0 to 30 Steps

      MAP

      (Data List)

      		 (EGR valve is fully closed) MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

      Tech Tips


      • While performing the Active Test, if the increase in the value of MAP is small, the EGR valve assembly may be a malfunctioning.

      • Even if the EGR valve assembly is malfunctioning, rough idling or an increase in the value of MAP may occur while performing the Active Test. However, the amount that the value of MAP increases will be smaller than normal.

      Result
      Result Proceed to
      Outside of standard range A
      Within standard range B

    B

    REPLACE ECM Click here

    A

  13. INSPECT EGR VALVE ASSEMBLY


    1. Remove the EGR valve assembly Click here.

    2. Check if the EGR valve is stuck open.

      OK
      EGR valve us tightly closed.

    NG

    REPLACE EGR VALVE ASSEMBLY Click here

    OK

  14. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  15. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the power switch off and wait for 30 seconds.

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

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

    8. Input the DTC: P2195 or P2196.

    9. 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

    END

  16. REPLACE AIR FUEL RATIO SENSOR NO.2


    1. Replace the air fuel ratio sensor Click here.


    NEXT

  17. PERFORM CONFIRMATION DRIVING PATTERN


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the power switch off and wait for 30 seconds.

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

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

    8. Input the DTC: P2195 or P2196.

    9. Check the DTC judgment result.

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

    A

    END

    B

    REPLACE ECM Click here

  18. CHECK FUEL LINE


    1. Check the fuel lines for leaks or blockage.


    OK

    REPLACE FUEL PUMP Click here

    NG

    REPAIR OR REPLACE FUEL LINE