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Home >> Lexus >> 2008 >> IS 250 RWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 171 (Engine Control System - SFI System Diagnostics (2 Of 4)) >> DTC P0441 Evaporative Emission Control System Incorrect Purge Flow >> OBD II Monitor Specifications

OBD II Monitor Specifications

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.
  1. Key-off Monitor 

    Monitor Strategy 

    MONITOR STRATEGY CHART

    Required Sensors/Components Purge VSV and canister pump module
    Frequency of Operation Once per driving cycle
    Duration Within 15 minutes (varies with amount of fuel in tank)
    MIL Operation 2 driving cycles
    Sequence of Operation None

    Typical Enabling Conditions 

    TYPICAL ENABLING CONDITIONS CHART

    EVAP key-off monitor runs when all of the following conditions met -
    Atmospheric pressure 70 to 110 kPa-a (525 to 825 mmHg-a)
    Battery voltage 10 5 V or more
    Vehicle speed Below 2 5 mph (4 km/h)
    Engine switch off
    Time after key off 5 or 7 or 9 5 hours
    Canister pressure sensor malfunction (P0451, P0452 and P0453) Not detected
    Purge VSV Not operated by scan tool
    Vent valve Not operated by scan tool
    Leak detection pump Not operated by scan tool
    Both of the following conditions met before key off Conditions 1 and 2
    1 Duration that vehicle driven 5 minutes or more
    2 EVAP purge operation Performed
    Engine coolant temperature 4 4 to 35°C (40 to 95°F)
    Intake air temperature 4 4 to 35°C (40 to 95°F)

    Typical Malfunction Thresholds 

    TYPICAL MALFUNCTION THRESHOLDS CHART

    Purge VSV stuck open -
    EVAP pressure when vacuum introduction complete Higher than reference pressure x 0 32
    TYPICAL MALFUNCTION THRESHOLDS CHART

    Purge VSV stuck closed -
    EVAP pressure change after purge VSV ON (open) Less than 0 3 kPa-g (2 25 mmHg-g)
  2. Key-off monitor sequence 1 to 8 
    1. Atmospheric Pressure Measurement 
      TYPICAL MALFUNCTION THRESHOLDS CHART

      Next sequence run if following condition set -
      Atmospheric pressure change Less than 0 3 kPa-g (2 25 mmHg-g) in 1 second
    2. First Reference Pressure Measurement 
      TYPICAL MALFUNCTION THRESHOLDS CHART

      Next sequence run if all of the following conditions set Condition 1, 2 and 3
      1 EVAP pressure just after reference pressure measurement started -1 kPa-g (-7 5 mmHg-g) or less
      2 Reference pressure -4 85 to -1 057 kPa-g (-36 4 to -7 93 mmHg-g)
      3 Reference pressure Saturated within 60 seconds
    3. Vent Valve Stuck Closed Check 
      TYPICAL MALFUNCTION THRESHOLDS CHART

      Next sequence run if following condition set -
      EVAP pressure change after vent valve ON (closed) 0 3 kPa-g (2 25 mmHg-g) or more
    4. Vacuum Introduction 
      TYPICAL MALFUNCTION THRESHOLDS CHART

      Next sequence run if following condition set -
      EVAP pressure Saturated within 15 minutes
    5. Purge VSV Stuck Closed Check 
      TYPICAL MALFUNCTION THRESHOLDS CHART

      Next sequence run if following condition set -
      EVAP pressure change after purge VSV ON (open) 0 3 kPa-g (2 25 mmHg-g) or more
    6. Second Reference Pressure Measurement 
      TYPICAL MALFUNCTION THRESHOLDS CHART

      Next sequence run if all of the following conditions set Condition 1,2,3 and 4
      1 EVAP pressure just after reference pressure -1 kPa-g (-7 5 mmHg-g) or less
      2 Reference pressure -4 85 to -1 057 kPa-g (-36 4 to -7 93 mmHg-g)
      3 Reference pressure Saturated within 60 seconds
      4 Reference pressure difference between first and second Less than 0 7 kPa-g (5 25 mmHg-g)
    7. Leak Check 
      TYPICAL MALFUNCTION THRESHOLDS CHART

      Next sequence run if following condition set -
      EVAP pressure when vacuum introduction complete Second reference pressure or less
    8. Atmospheric Pressure Measurement 
      TYPICAL MALFUNCTION THRESHOLDS CHART

      EVAP monitor complete if following condition set -
      Atmospheric pressure difference between sequence 1 and 8 Within 0 3 kPa-g (2 25 mmHg-g)


  1. Purge Flow Monitor 

    Monitor Strategy 

    MONITOR STRATEGY CHART

    Required Sensors/Components Purge VSV and canister pump module
    Frequency of Operation Once per driving cycle
    Duration Within 10 minutes
    MIL Operation 2 driving cycles
    Sequence of Operation None

    Typical Enabling Conditions 

    TYPICAL ENABLING CONDITIONS CHART

    Monitor runs whenever following DTCs not present P0011 (VVT System 1 - Advance)
    P0012 (VVT System 1 - Retard)
    P0021 (VVT System 2 - Advance)
    P0022 (VVT System 2 - Retard)
    P0101 - P0103 (Mass air flow meter)
    P0112, P0113 (Intake air temperature sensor)
    P0115 - P0118 (Engine coolant temperature sensor)
    P0120 - P0223, P2135 (Throttle position sensor)
    P0125 (Insufficient engine coolant temperature for Closed Loop)
    P0171, P0172, P0173, P0174 (Fuel system)
    P0300 - P0308 (Misfire)
    P0335 (Crankshaft position sensor)
    P0340 (VVT sensor)
    P0351 - P0358 (Igniter)
    P0451 - P0453 (Canister pressure sensor)
    P0500 (Vehicle speed sensor)
    Engine Running
    Engine coolant temperature 4 4°C (40°F) or more
    Intake air temperature 4 4°C (40°F) or more
    Canister pressure sensor malfunction Not detected
    Purge VSV Not operated by scan tool
    EVAP system check Not operated by scan tool
    Battery voltage 10 V or more
    Purge duty cycle 8% or more

    Typical Malfunction Thresholds 

    TYPICAL MALFUNCTION THRESHOLDS CHART

    Both of the following conditions met Conditions 1 and 2
    1 EVAP pressure change when purge operation started Less than 0 1 kPa-g (0 75 mmHg-g)
    2 EVAP pressure change during purge operation when vent valve closed Less than 0 3 kPa-g (2 25 mmHg-g)