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Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

It is possible the malfunctioning area can be found using the ACTIVE TEST A/F CONTROL operation.

The ACTIVE TEST can determine if the heated oxygen sensor or other potential trouble areas are malfunctioning or not.

The injection volume can be switched to -12.5% (decrease) or +25% (increase) by the ACTIVE TEST. The ACTIVE TEST procedure enables a technician to check and graph the output voltage of the heated oxygen sensors.

Procedure:

  1. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
  2. Turn the ignition switch ON.
  3. Warm up the engine by running the engine at 2,500 rpm for approximately 90 seconds.
  4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
  5. Perform the ACTIVE TEST while the engine is idling.

    Standard: 

    The heated oxygen sensor reacts in accordance with the increase and decrease of injection volume: 

    +25% → RICH output: More than 0.55 V 

    -12.5% → LEAN output: Less than 0.4 V 

    NOTE: The heated oxygen sensor (sensor 1) output has a few seconds of delay and the heated oxygen sensor (sensor 2) output has a maximum of 20 seconds of delay.
    If the vehicle is short on fuel, the air-fuel ratio becomes LEAN and the DTCs will be recorded.
    Fig 1: Heated Oxygen Sensor Voltage - Blinking Pattern
    G05291368Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

  1. CHECK OTHER DTC OUTPUT 
    1. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
    2. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO/ CURRENT CODES.
    3. Read the DTCs.

      Result 

      RESULT CHART

      Display (DTC output) Proceed to
      P0134 or P0154 A
      P0134 or P0154 and other DTCs B

    B: GO TO RELEVANT DTC CHART 

    A: Go to next step 

  2. READ VALUE OF INTELLIGENT TESTER (HEATED OXYGEN SENSOR (SENSOR 1) VOLTAGE) 
    1. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
    2. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / O2S B1 S1 (or O2S B2 S1).
    3. Allow the engine to idle until the ECT reaches 40°C (104°F).
    4. Quickly depress the accelerator pedal 3 times until the engine RPM reaches 4,000 rpm. Then, read the heated oxygen sensor voltage.

      Standard voltage: 

      The heated oxygen sensor voltage is 0.45 V or more at least once. 

    OK: Go to step  11

    NG: Go to next step 

  3. CHECK CONNECTION PCV HOSE 

    OK: 

    PCV hose is connected correctly and is not damaged. 

    NG: REPAIR OR REPLACE PCV HOSE 

    OK: Go to next step 

  4. INSPECT HEATED OXYGEN SENSOR 
    Fig 2: Identifying Heated Oxygen Sensor Connector Terminals
    G05291369Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the H9 and H10 sensor connectors.
    2. Measure the resistance of the sensor.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      1 (HT) - 2 (+B) 11 to 16 Ω
      1 (HT) - 4 (E1) 10 kΩ or higher

    NG: REPLACE HEATED OXYGEN SENSOR 

    OK: Go to next step 

  5. INSPECT EFI RELAY (Marking: EFI) 
    Fig 3: Inspecting EFI Relay
    G05291370Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the EFI relay from the engine room No. 2 relay block.
    2. Measure the resistance of the EFI relay.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      3 - 5 10 kΩ or higher
      3 - 5 Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

    NG: REPLACE EFI RELAY 

    OK: Go to next step 

  6. CHECK WIRE HARNESS (HEATED OXYGEN SENSOR (SENSOR 1) - ECM) 
    1. Disconnect the H9 and H10 sensor connectors.
    2. Disconnect the E2 and E4 ECM connectors.
      Fig 4: Disconnecting E2 And E4 ECM Connector Terminals
      G05291371Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance of the wire harness side connectors.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      H9-1 (HT) - E2-24 (HT1A) Below 1 Ω
      H9-3 (OX) - E2-30 (0X1 A) Below 1 Ω
      H10-1 (HT) - E4-5 (HT2A) Below 1 Ω
      H10-3 (OX) - E4-28 (OX2A) Below 1 Ω
      H9-1 (HT) or E2-24 (HT1A) - Body ground 10 kΩ or higher
      H9-3 (OX) or E2-30 (OX1A) - Body ground 10 kΩ or higher
      H10-1 (HT) or E4-5 (HT2A) - Body ground 10 kΩ or higher
      H10-3 (OX) or E4-28 (OX2A) - Body ground 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: Go to next step 

  7. CHECK AIR INDUCTION SYSTEM 
    1. Check the air induction system for vacuum leaks.

      OK: 

      There are no vacuum leaks in air induction system. 

    NG: REPAIR OR REPLACE AIR INDUCTION SYSTEM 

    OK: Go to next step 

  8. CHECK FUEL PRESSURE 
    1. Check the fuel pressure (see ON-VEHICLE INSPECTION ).

    NG: REPAIR OR REPLACE FUEL SYSTEM 

    OK: Go to next step 

  9. INSPECT FUEL INJECTOR 
    1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor).

    NG: REPLACE FUEL INJECTOR 

    OK: Go to next step 

  10. CHECK FOR EXHAUST GAS LEAKAGE 

    NG: REPAIR OR REPLACE EXHAUST SYSTEM 

    OK: REPLACE HEATED OXYGEN SENSOR 

  11. PERFORM CONFIRMATION DRIVING PATTERN 

    HINT:

    Clear all DTCs before performing the confirmation driving pattern.

  12. READ OUTPUT DTC (DTC P0134 OR P0154 IS OUTPUT AGAIN) 
    1. Clear the DTC (see DTC CHECK/CLEAR  ).
    2. Start the engine and allow the engine to idle for 15 seconds or more.
    3. Read the DTC.

      Result 

      RESULT CHART

      Display (DTC output) Proceed to
      None A
      P0134 or P0154 B

    B: REPLACE ECM 

    A: Go to next step 

  13. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL 
    1. If the vehicle has run out of fuel, proceed to A.
    2. If the vehicle has not run out of fuel, proceed to B.

    B: CHECK FOR INTERMITTENT PROBLEMS 

    A: DTC IS CAUSED BY RUNNING OUT OF FUEL