Inspection Procedure

HINT:

It is possible the malfunctioning area can be found using the Active Test Control the Injection Volume for A/F Sensor 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 Techstream 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: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
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.
   FRONT HO2 SENSOR VOLTAGE CHART
   
   

   Case	Front HO2 Sensor (Sensor 1) Output Voltage	Rear HO2 Sensor (Sensor 2) Output Voltage	Main Suspected Trouble Area
   1	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	-
   2	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Front HO2 sensor Front HO2 sensor heater Front HO2 sensor circuit
   3	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Rear HO2 sensor Rear HO2 sensor heater Rear HO2 sensor circuit
   4	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002	Injector Fuel pressure Gas leakage from exhaust system (Air-fuel ratio extremely rich or lean)

   HINT:

   • Read freeze frame data using the Techstream. 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.
   • Bank 1 refers to the bank that includes No. 1 cylinder.
   • Bank 2 refers to the bank that does not include No. 1 cylinder.
   • No. 1 cylinder is located in the front part of the engine, opposite the transmission.
   • Sensor 1 refers to the sensor closest to the engine body.

1. CHECK OTHER DTC OUTPUT 
   1. Connect the Techstream to the DLC3.
   2. Enter the following menus: Powertrain / Engine and ECT / Trouble 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 TECHSTREAM (HEATED OXYGEN SENSOR (SENSOR 1) VOLTAGE) 
   1. Connect the Techstream to the DLC3.
   2. Enter the following menus: Powertrain / Engine and ECT / 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 
   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 

      Fig 1: Inspecting Heated Oxygen Sensor

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to Next Step 

5. INSPECT EFI RELAY (Marking: EFI) 
   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 

      Fig 2: EFI Relay Circuit Diagram

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      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.
   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 (OX1A)	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 

      Fig 3: Checking Wire Harness (Heated Oxygen Sensor (Sensor 1) - ECM)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      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