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Inspection Procedure

HINT:

Hand-held tester only:

It is possible the malfunctioning area can be found using the ACTIVE TEST A/F CONTROL operation. The A/F CONTROL operation can determine if the A/F sensor, heated oxygen sensor or other potential trouble areas are malfunctioning or not.

  1. Perform the ACTIVE TEST A/F CONTROL operation.

    HINT:

    The A/F CONTROL operation lowers the injection volume 12.5% or increases the injection volume 25%.

    1. Connect the hand-held tester to the DLC3 on the vehicle.
    2. Turn the ignition switch to ON.
    3. Warm up the engine by running the engine at 2,500 rpm for approximately 90 seconds.
    4. Select the item: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
    5. Perform the A/F CONTROL operation with the engine in an idle condition (press the right or left button).
  1. Result: 
  2. A/F sensor reacts in accordance with increase and decrease of injection volume: 
  3. +25 % --> rich output: Less than 3.0 V 
  4. -12.5 % --> lean output: More than 3.35 V 
  5. Heated oxygen sensor reacts in accordance with increase and decrease of injection volume: 
  6. +25 % --> rich output: More than 0.55 V 
  7. -12.5 % --> lean output: Less than 0.4 V 
NOTE: The A/F sensor output has a few seconds of delay and the heated oxygen sensor output has about 20 seconds of delay at maximum.
Fig 1: A/F Sensor, Heated Oxygen Sensor Output Voltage Graphical Representation
G02937581Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

The following A/F CONTROL procedure enables the technician to check and graph the voltage outputs of both the A/F sensor and the heated oxygen sensor.

To display the graph, enter ACTIVE TEST/ A/F CONTROL/USER DATA, then select "AFS B1S1 and O2S B1S2" or "AFS B2S1 and O2S B2S2" by pressing the "YES" button followed by the "ENTER" button and then the "F4" button.

HINT:

Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.

  1. CHECK OTHER DTC OUTPUT 
    1. Read the DTC using the hand-held tester or the OBD II scan tool.

      Result: 

      DTC OUTPUT RESULT

      Display (DTC Output) Proceed to
      P0138 or P0158 is output A
      P0137 or P0157 is output B
      P0136 or P0156 is output C

      HINT:

      If any other codes besides P0136, P0137, P0138, P0156, P0157 and/or P0158 are output, perform the troubleshooting for those codes first.

      B: Go to step   9 

      C: Go to step   6 

      A: GO TO NEXT STEP 

  2. READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR) 
    1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
    2. Turn ON the ignition switch. Push the hand-held tester or the OBD II scan tool main switch ON.
    3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / O2S B1S2.
    4. Run the engine at idle.
    5. Read the output voltage of the heated oxygen sensor during idling.
    HEATED OXYGEN SENSOR OUTPUT VOLTAGE

    Heated oxygen sensor output voltage Proceed to
    More than 1.2 V A
    Less than 1.0 V B

    B: Go to step   5 

    A: GO TO NEXT STEP 

  3. CHECK WIRE HARNESS (CHECK FOR SHORT) 
    1. Turn the ignition switch OFF and wait for 5 minutes.
    2. Disconnect the E9 ECM connector.
    3. Measure the resistance of the wire harness side connectors.

    Standard: 

    TESTER CONNECTION SPECIFIED CONDITION

    Tester Connection Specified Condition
    E9-25 (HT1B) - E9-21 (OX1B) No continuity

    OK: REPLACE ECM 

    NG: GO TO NEXT STEP 

    Fig 2: Disconnecting E9 ECM Connector
    G02937582Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. INSPECT HEATED OXYGEN SENSOR 
    1. Disconnect the H9 or H10 heated oxygen sensor connector.
    2. Measure the resistance of the sensor side connectors.

    Standard: 

    TESTER CONNECTION SPECIFIED CONDITION

    Tester Connection Specified Condition
    H9-2 (+B) - H9-4 (E1) 10 kΩ or higher
    H9-2 (+B) - H9-3 (OX) 10 kΩ or higher
    H10-2 (+B) - H10-4 (E1) 10 kΩ or higher
    H10-2 (+B) - H10-3 (OX) 10 kΩ or higher

    OK: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    Fig 3: Identifying H9 And H10 Heated Oxygen Sensor Connector For Measuring Resistance
    G02937583Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE HEATED OXYGEN SENSOR 

  5. READ OUTPUT DTC (CHECK MODE) 
    1. Change the ECM to check mode with the hand-held tester.

      Enter the following menus: DIAGNOSIS / ENHANCED OBD II / CHECK MODE.

    2. Warm up the engine and drive the vehicle at over 25 mph (40 km/h) for an accumulated total of 10 minutes.

      HINT:

      The 10 minutes of driving should be driven in one instance, but it is not necessary to maintain a speed of 25 mph (40 km/h) for 10 minutes consecutively.

    3. Read the DTC.

      Result: 

    DTC OUTPUT RESULT

    Display (DTC output) Proceed to
    P0138 or P0158 is output A
    No DTC B

    B: CHECK FOR INTERMITTENT PROBLEMS 

    A: REPLACE HEATED OXYGEN SENSOR 

  6. READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (OUTPUT VOLTAGE OF HEATED OXYGEN SENSOR) 
    1. After warming up the engine, run the engine at 2,500 rpm for 3 minutes.
    2. Read the output voltage of the heated oxygen sensor when the engine rpm is suddenly increased.

    HINT:

    Quickly accelerate the engine to 4,000 rpm 3 times by using the accelerator pedal.

    Heated oxygen sensor output voltage: Alternates 0.4 V or less and 0.5 V or more. 

    OK: Go to step   10 

    NG: GO TO NEXT STEP 

  7. INSPECT HEATED OXYGEN SENSOR 
    1. Disconnect the H9 or H10 heated oxygen sensor connector.
    2. Measure the resistance between the terminals of the heated oxygen sensor connector.

    Standard (Bank 1, 2 sensor 2): 

    TESTER CONNECTION SPECIFIED CONDITION

    Tester Connection Specified Condition
    HT (H9-1) - +B (H9-2) 11 to 16 Ω at 20 °C (68 °F)
    HT (H9-1) - E1 (H9-4) 10 kΩ or higher
    HT (H10-1) - +B (H10-2) 11 to 16 Ω at 20 °C (68 °F)
    HT (H10-1) - E1 (H10-4) 10 kΩ or higher

    NG: REPLACE HEATED OXYGEN SENSOR 

    OK: GO TO NEXT STEP 

    Fig 4: Identifying H9 Or H10 Heated Oxygen Sensor Connector Terminal
    G02937584Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  8. INSPECT RELAY 
    1. Remove the EFI relay from the engine room J/B.
    2. Check for continuity in the EFI relay.

      Standard: 

      Fig 5: Inspecting EFI Relay For Continuity
      G02937585Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 6: Tester Connection Specified Condition Table
      G02937586Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reinstall the EFI relay.

    NG: REPLACE RELAY 

    OK: GO TO NEXT STEP 

  9. CHECK WIRE HARNESS 
    1. Disconnect the H9 or H10 heated oxygen sensor connector.
    2. Disconnect the E9 ECM connector.
    3. Check the resistance between the wire harness side connectors.

      Standard (Check for open): 

      Fig 7: Identifying H9 or H10 Heated Oxygen Sensor Connector Terminals
      G02937587Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 8: Disconnecting E9 ECM Connectors
      G02937588Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 9: Tester Connection Specified Condition Table
      G02937589Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard (Check for short): 

      Fig 10: Tester Connection Specified Condition Table
      G02937590Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. Reconnect the heated oxygen sensor connector.
    5. Reconnect the ECM connector.
      Fig 11: Bank 1 Sensor 2 System Wiring Diagram
      G02937591Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: REPLACE HEATED OXYGEN SENSOR 

  10. PERFORM  CONFIRMATION DRIVING PATTERN  

    HINT:

    Clear all DTCs prior to performing the CONFIRMATION DRIVING PATTERN .

    NEXT: GO TO NEXT STEP 

  11. READ OUTPUT DTC (DTC P0136 OR P0156 IS OUTPUT AGAIN) 
    1. Read the DTC using the hand-held tester or the OBD II scan tool.

      Result: 

      DTC OUTPUT

      Display (DTC Output) Proceed to
      P0136 or P0156 is not output again A
      P0136 or P0156 is output again B

      A: CHECK FOR INTERMITTENT PROBLEMS 

      B: GO TO NEXT STEP 

  12. REPLACE HEATED OXYGEN SENSOR 

    NEXT: GO TO NEXT STEP 

  13. PERFORM  CONFIRMATION DRIVING PATTERN  

    HINT:

    Clear all DTCs prior to performing the CONFIRMATION DRIVING PATTERN .

    NEXT: GO TO NEXT STEP 

  14. READ OUTPUT DTC (DTC P0136 OR P0156 IS OUTPUT AGAIN) 
    1. Read the DTC using the hand-held tester or the OBD II scan tool.

    Result: 

    DTC OUTPUT RESULT

    Display (DTC Output) Proceed to
    P0136 or P0156 is not output again A
    P0136 or P0156 is output again B

    A: REPAIR COMPLETED 

    B: GO TO NEXT STEP 

  15. PERFORM ACTIVE TEST USING HAND-HELD TESTER 
    1. Start the engine and warm it up.
    2. Connect the hand-held tester to the DLC3.
    3. Turn ON the ignition switch and the hand-held tester main switch.
    4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / INJ VOL.
    5. Using the hand-held tester, change the injection volume to check the A/F sensor output and heated oxygen sensor output values below.

    HINT:

    Change the injection volume from -12.5 % to +12.5 %.

    1. Result: 
    2. A/F sensor output remains more than 3.3 V or A/F sensor output remains less than 3.3 V (Heated oxygen sensor reacts in accordance with increase and decrease of injection volume) 
    Fig 12: Graph Checking A/F Sensor, Heated Oxygen Sensor Output Value
    G02937592Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPLACE AIR FUEL RATIO SENSOR 

    NG: CHECK AND REPLACE EXTREMELY RICH OR LEAN ACTUAL AIR FUEL RATIO 

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