Inspection Procedure

HINT:

• If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
• If any of DTC P0441 (Purge Flow), P0446 (VSV for CCV), P0451, P0452 or P0453 (Evaporative Pressure Sensor) are set simultaneously with DTC P0442 or P0456, troubleshoot DTC P0441, P0446, P0451, P0452 or P0453 first. If no malfunction is detected, troubleshoot DTC P0442 or P0456 next.
• Read freeze frame data using a hand-held tester or OBD II scan tool. Freeze frame data record 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.
• If the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the vapor pressure sensor.

1. INSPECT ECM (VC VOLTAGE) 
   1. Turn the ignition switch to ON.
   2. Measure the voltage between the terminals of the E3 ECM connector.

   Standard: 

   TESTER CONNECTIONS SPECIFIED CONDITION (1 OF 3)
   
   

   Tester Connections	Specified Conditions
   VC (E3-18) - E2 (E3-28)	Between 4.5 V and 5.5 V

   Fig 1: Inspecting ECM (VC Voltage)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPLACE ECM (See  REPLACEMENT  ) 

   OK: Go to next step. 

2. INSPECT ECM (PTNK VOLTAGE) 
   1. Turn the ignition switch to ON.
   2. Measure the voltage between the terminals of the E3 and E6 ECM connectors.
      1. Remove the vapor pressure sensor.

         Standard (1): 

         TESTER CONNECTIONS SPECIFIED CONDITION (2 OF 3)
         
         

         Tester Connections	Specified Conditions
         PTNK (E6-21) - E2 (E3-28)	Between 2.9 V and 3.7 V

      2. Using a 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): 

         TESTER CONNECTIONS SPECIFIED CONDITION (3 OF 3)
         
         

         Tester Connections	Specified Conditions
         PTNK (E6-21) - E2 (E3-28)	0.5 V or less

      3. Reinstall the vapor pressure sensor.
   Fig 2: Inspecting ECM (PTNK Voltage)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: REPLACE ECM (See  REPLACEMENT  ) 

   NG: Go to next step. 

3. CHECK HARNESS AND CONNECTOR (VAPOR PRESSURE SENSOR - ECM) 
   1. Disconnect the V7 vapor pressure sensor connector.
   2. Disconnect the E3 and E6 ECM connectors.
   3. Check the resistance.
      Fig 3: Identifying V7 Vapor Pressure Sensor Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard (Check for open): 

      TESTER CONNECTIONS SPECIFIED CONDITION (FOR OPEN)
      
      

      Tester Connections	Specified Conditions
      PTNK (V7-2) - PTNK (E6-21)	Below 1 Ω
      GND (V7-1) - E2 (E3-28)	Below 1 Ω
      VCC (V7-3) - VC (E3-18)	Below 1 Ω

      Standard (Check for short): 

      TESTER CONNECTIONS SPECIFIED CONDITION (FOR SHORT)
      
      

      Tester Connections	Specified Conditions
      PTNK (V7-2) or PTNK (E6-21) - Body ground	10 kΩ or higher
      VCC (V7-3) or VC (E3-18) - Body ground	10 kΩ or higher

   4. Reconnect the ECM connectors.
   5. Reconnect the vapor pressure sensor connector.
   Fig 4: Disconnecting E3 And E6 ECM Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE VAPOR PRESSURE SENSOR ASSY