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

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.

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. The heat generated by the heater is conducted to the solid electrolyte through the alumina, thereby accelerating the sensor activation.

A three way catalytic converter is used in order to convert the carbon monoxide, hydrocarbons and nitrogen oxide 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.

*: The value changes inside the ECM. Since the air fuel ratio sensor is a current output element, 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.

A01DNRME01
DTC No. DTC Detection Condition Trouble Area
P2195

Conditions (a) and (b) are met for 10 seconds or more (2 trip detection logic):

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

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


  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor heater and relay circuits

  • 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 3.6 mA or higher (2 trip detection logic).
  • Air fuel ratio sensor

  • ECM

P2196

Conditions (a) and (b) are met for 10 seconds or more (2 trip detection logic):

(a) The air fuel ratio sensor voltage is below 2.8 V for 10 seconds.

(b) The heated oxygen sensor voltage is below 0.6 V.


  • Open or short in air fuel ratio sensor circuit

  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor heater and relay circuits

  • 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 0.78 mA (2 trip detection logic).
  • Air fuel ratio sensor

  • ECM

Tech Tips


  • When either of these DTCs is stored, check the air fuel ratio sensor output voltage using the intelligent tester. Enter the following menus: Powertrain / Engine and ECT / Data List / 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

A01DMSKE01

CONFIRMATION DRIVING PATTERN


INSPECTION PROCEDURE

Note

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

Tech Tips

Intelligent tester only:

Malfunctioning areas can be identified by performing the "Control the Injection Volume for A/F Sensor" function provided in the Active Test. The "Control the Injection Volume for A/F Sensor" function can help 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 for A/F Sensor" 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 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 (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


  • The "Control the Injection Volume for A/F Sensor" operation lowers the fuel injection volume by 12.5% or increases the injection volume by 12.5%.

  • The sensors react in accordance with increases and decreases in the fuel injection volume.

Standard

Tester Display

(Sensor)

Injection Volume Status Voltage

AFS Voltage B1S1

(Air fuel ratio sensor)

+12.5% Rich Below 3.1 V
-12.5% Lean Higher than 3.4 V

O2S B1S2

(Heated oxygen sensor)

+12.5% Rich Higher than 0.55 V
-12.5% Lean Below 0.4 V

Note

The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor (sensor 2) output has a maximum output delay of approximately 20 seconds.

Case

Air Fuel Ratio Sensor

Output Voltage

Heated Oxygen Sensor

Output Voltage

Main Suspected Trouble Area
1 A01DTIDE23 A01DMIIE15 -
2 A01DMZLE18 A01DMIIE15
  • Air fuel ratio sensor

  • Air fuel ratio sensor heater

  • Air fuel ratio sensor circuit

3 A01DTIDE23 A01DMZLE18
  • Heated oxygen sensor

  • Heated oxygen sensor heater

  • Heated oxygen sensor circuit

  • Exhaust gas leakage

4 A01DMZLE18 A01DMZLE18
  • Fuel pressure

  • Exhaust gas leakage

    (Air fuel ratio extremely lean or rich)


Tech Tips


  • DTC P2A00 may be stored when the air fuel ratio is stuck rich or 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.

  • 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.

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 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
    A
  2. READ VALUE USING INTELLIGENT TESTER (TEST VALUE OF AIR FUEL RATIO SENSOR)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Clear the DTCs Click here.

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

    6. Enter the following menus: Powertrain / Engine and ECT / Utility / Monitor Status.

    7. Check that the status of "O2 Sensor" is "Complete".

      If the status is still "Incomplete", drive the vehicle according to the driving pattern again.

      Tech Tips


      • "Available" indicates that the component has not been monitored yet.

      • "Complete" indicates that the component is functioning normally.

      • "Incomplete" indicates that the component is malfunctioning.

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

    9. Check the test value of the air fuel ratio sensor output current during fuel-cut (refer to Monitor Driving Pattern 2 [Detail for "C" through "F"] in Confirmation Driving Pattern).

      Result
      Test Value Proceed to
      Within normal range (1.0 mA or higher, and below 3.6 mA) A
      Outside normal range (Below 1.0 mA, or 3.6 mA or higher) B

    B
    A
  3. 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 and ECT / Data List / AFS Voltage B1S1 and Engine Speed / Function / Snap Shot Record.

    6. Check the air fuel ratio sensor voltage 3 times, once under each of the following conditions:


      1. Engine idling (for at least 30 seconds) (Step "A").

      2. Engine running at an engine speed of approximately 2500 rpm (without any sudden changes in engine speed) (Step "B").

      3. Engine speed to raised 4000 rpm and then accelerator pedal quickly released so that throttle valve is fully closed (Step "C").

        Standard Voltage
        Condition A/F Sensor Voltage Variation Reference
        Step "A" and Step "B" Remains at approximately 3.3 V Between 3.1 V and 3.5 V
        Step "C" Increases to 3.8 V or higher

        Occurs during engine deceleration

        (when fuel-cut performed)

      Tech Tips


      • For more information, see the diagrams below.

        A01DSYXE70
      • If the output voltage of the air fuel ratio sensor remains at approximately 3.3 V (see "Malfunctioning" diagram) under any conditions, including those above, the air fuel ratio sensor may have an open circuit (this will also happen if the air fuel ratio sensor heater has an open circuit).

      • If the output voltage of the air fuel ratio sensor remains at either approximately 3.8 V or higher, or 2.8 V or less (see "Malfunctioning" diagram) under any conditions, including those above, the air fuel ratio sensor may have a short circuit.

      • The ECM stops fuel injection (fuel cut) during engine deceleration. This causes a lean condition and results in a momentary increase in the air fuel ratio sensor output voltage.

      • The ECM must establish a closed throttle valve position learned value to perform fuel cut. If the battery cable has been disconnected and reconnected, the vehicle must be driven over 16 km/h (10 mph) to allow the ECM to learn the closed throttle valve position.

      • When the vehicle is driven:

        The output voltage of the air fuel ratio sensor may be below 2.8 V during fuel enrichment. For the vehicle, this translates to a sudden increase in speed with the accelerator pedal fully depressed when trying to overtake another vehicle. The air fuel ratio sensor is functioning normally.

      • The air fuel ratio sensor is a current output element. Therefore, the current is converted into a voltage inside the ECM. Measuring the voltage at the connectors of the air fuel ratio sensor or ECM will show a constant voltage.


    NG
    OK
  4. PERFORM CONFIRMATION DRIVING PATTERN


    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. Turn the ignition switch to ON and turn the intelligent 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.


    NEXT
  5. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)


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

    2. Input the DTC: P2195 or P2196.

    3. Check the DTC judgment result.

      Result
      Result Proceed to
      ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output) A
      NORMAL (DTC is not output) B

    B
    A
  6. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT
  7. PERFORM CONFIRMATION DRIVING PATTERN


    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. Turn the ignition switch to ON and turn the intelligent 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.


    NEXT
  8. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)


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

    2. Input the DTC: P2195 or P2196.

    3. Check the DTC judgment result.

      Result
      Result Proceed to
      ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output) A
      NORMAL (DTC is not output) B

    B
    A
  9. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST


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


    NO
    YES
  10. INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)


    1. Inspect the air fuel ratio sensor Click here.


    NG
    OK
  11. CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)


    1. Disconnect the air fuel ratio sensor connector.

    2. Disconnect the ECM connector.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      C56-2 (+B) - Body ground Ignition switch ON 11 to 14 V
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      C56-1 (HA1A) - C63-6 (HA1A) Always Below 1 Ω
      C56-3 (A1A+) - C63-7 (A1A+) Always Below 1 Ω
      C56-4 (A1A-) - C63-1 (A1A-) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C56-1 (HA1A) or C63-6 (HA1A) - Body ground Always 10 kΩ or higher
      C56-3 (A1A+) or C63-7 (A1A+) - Body ground Always 10 kΩ or higher
      C56-4 (A1A-) or C63-1 (A1A-) - Body ground Always 10 kΩ or higher
    5. Reconnect the ECM connector.

    6. Reconnect the air fuel ratio sensor connector.

      A01DR3QE01

    NG
    OK
  12. CHECK INTAKE SYSTEM


    1. Check the intake system for vacuum leakage.

      OK
      No leakage from intake system.

    NG
    OK
  13. CHECK FUEL PRESSURE


    1. Check the fuel pressure Click here.


    NG
    OK
  14. INSPECT FUEL INJECTOR ASSEMBLY


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


    NG
    OK
  15. REPLACE AIR FUEL RATIO SENSOR


    1. Replace the air fuel ratio sensor Click here.


    NEXT
  16. PERFORM CONFIRMATION DRIVING PATTERN


    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. Turn the ignition switch to ON and turn the intelligent 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.


    NEXT
  17. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195 OR P2196)


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

    2. Input the DTC: P2195 or P2196.

    3. Check the DTC judgment result.

      Result
      Result Proceed to
      ABNORMAL (DTC P2195, P2196, P2197 or P2198 is output) A
      NORMAL (DTC is not output) B

    B
    A