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Home >> Scion >> 2004 >> xA Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnosis >> DTC P0442, DTC P0456: Evaporative Emission Control System Leak Detected >> Inspection Procedure

Inspection Procedure

NOTE:
  • If DTC P0441 (Purge Flow), P0446 (VSV for CCV) or P0451 (Evaporative Pressure Sensor) is output with DTC P0442 or P0456, first troubleshoot DTC P0441, P0446 or P0451. If no malfunction is detected, troubleshoot DTC P0442 or P0456 next.
  • Ask the customer whether, after the MIL came on, the customer found the fuel tank cap loose and tightened it. Also ask the customer whether the fuel tank cap was loose when refuelling. If the fuel tank cap was loose, it was the cause of the DTC. If the fuel tank cap was not loose or if the customer was not sure if it was loose, troubleshoot according to the following procedure.
  • Read freeze frame data using hand-held tester or OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.
  • When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the vapor pressure sensor.
  1. CHECK FOR EVAPORATIVE EMISSIONS LEAK 
    1. Check if any hoses close to the fuel tank have been modified, and check if there are signs of any accident damage near the fuel tank or the charcoal canister.
      1. Check the following parts for cracks, deformation or loose connections:
        • Fuel tank
        • Charcoal canister
        • Fuel tank filler pipe
        • Hoses and tubes around fuel tank and charcoal canister
          Fig 1: Checking Evaporative Emissions Leak
          G03367176Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG : REPAIR OR REPLACE 
    2. OK : Go to next step. 
  2. INSPECT FUEL TANK CAP ASSY (CHECK THAT FUEL TANK IS GENUINE PARTS) 
    1. NG : REPLACE TO GENUINE PARTS 
    2. OK : Go to next step. 
  3. CHECK THAT FUEL TANK CAP IS CORRECTLY INSTALLED 
    1. NG : CORRECTLY INSTALL FUEL TANK CAP 
    2. OK : Go to next step. 
  4. INSPECT FUEL TANK CAP ASSY (See  INSPECTION  ) 
    1. NG : REPLACE FUEL TANK CAP ASSY 
    2. OK : Go to next step. 
  5. CHECK FILLER NECK FOR DAMAGE 
    1. NG : REPLACE FUEL TANK INLET PIPE SUB-ASSY 
    2. OK : Go to next step. 
  6. CHECK HOSES AND TUBES (VAPOR PRESSURE SENSOR - FUEL TANK) 
    1. Check that the vacuum hoses are connected correctly.
    2. Check that the vacuum hoses are not loose and disconnected.
    3. Check the vacuum hoses and tubes for cracks, holes, damage, or blockage.
    1. NG : REPAIR OR REPLACE HOSES AND TUBES 
    2. OK : Go to next step. 
  7. CHECK HOSES AND TUBES (FUEL TANK - CHARCOAL CANISTER) 
    1. Check the connection between the fuel tank and fuel EVAP pipe, fuel EVAP pipe and under-floor fuel tube, and under-floor fuel tube and charcoal canister.
    2. Check the hose and tube for cracks, hole and damage.
    1. NG : REPAIR OR REPLACE HOSES AND TUBES 
    2. OK : Go to next step. 
  8. INSPECT CHARCOAL CANISTER ASSY (CRACKS AND DAMAGE) 
    1. NG : REPLACE CHARCOAL CANISTER ASSY 
    2. OK : Go to next step. 
  9. INSPECT ECM (VC VOLTAGE) 
    Fig 2: Inspecting ECM (VC Voltage)
    G03367177Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Turn the ignition switch ON.
    2. Measure the voltage between the specified terminals of the E3 ECM connector.

      Standard: 

      STANDARD

      Tester Connection Specified Condition
      VC (E3-18) - E2 (E3-28) 4.5 to 5.5 V
    1. NG : REPLACE ECM (See  REPLACEMENT  ) 
    2. OK : Go to next step. 
  10. INSPECT ECM (PTNK VOLTAGE) 
    Fig 3: Inspecting ECM (PTNK Voltage)
    G03367178Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Turn the ignition switch ON.
    2. Measure the voltage between the specified terminals of the E3 and E6 ECM connectors.
      1. Remove the vapor pressure sensor.

        Standard (1): 

        STANDARD

        Tester Connection Specified Condition
        PTNK (E6-21) - E2 (E3-28) 2.9 to 3.7 V
      2. Using the MITYVAC (Hand-Held Vacuum Pump), apply a vacuum of 4.0 kPa (30 mmHg, 1.18 in.Hg) to the vapor pressure sensor.
        NOTE: The vacuum applied to the vapor pressure sensor must be less than 66.7 kPa (500 mmHg, 19.7 in.Hg).

        Standard (2): 

        STANDARD

        Tester Connection Specified Condition
        PTNK (E6-21) - E2 (E3-28) 0.5 V or less
      3. Reinstall the vapor pressure sensor.
    1. OK : Go to step   12 . 
    2. NG : Go to next step. 
  11. CHECK HARNESS AND CONNECTOR (VAPOR PRESSURE SENSOR - ECM) 
    1. Disconnect the V3 vapor pressure sensor connector.
      2. Fig 4: Disconnecting V3 Vapor Pressure Sensor Connector
      G03367179Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the E3 and E6 ECM connectors.
      3. Fig 5: Identifying E3 & E6 ECM Connectors
      G03367180Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance between the wire harness side connectors.

      Standard (Check for open): 

      STANDARD (CHECK FOR OPEN)

      Tester Connection Specified Condition
      PTNK (V3-2) - PTNK (E6-21) Below 1 Ω
      GND (V3-1) - E2 (E3-28)
      VCC (V3-3) - VC (E3-18)

      Standard (Check for short): 

      STANDARD (CHECK FOR SHORT)

      Tester Connection Specified Condition
      PTNK (V3-2) or PTNK (E6-21) - Body ground 10 kΩ or higher
      VCC (V3-3) or VC (E3-18) - Body ground
    4. Reconnect the vapor pressure sensor connector.
    5. Reconnect the ECM connector.
    1. NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 
    2. OK : REPLACE VAPOR PRESSURE SENSOR ASSY 
  12. CHECK FUEL TANK OVER FILL CHECK VALVE 
    1. NG : REPLACE FUEL TANK OVER FILL CHECK VALVE OR FUEL TANK 
    2. OK : IT IS LIKELY THAT FUEL TANK CAP WAS NOT CLOSED PROPERLY 
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