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Home >> Jeep >> 2005 >> Wrangler X, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 628 (Powertrain Diagnostic Procedures - DRIVEABILITY - NGC Symptoms & Diagnostic Tests (DTCS P0016 To P0563)) >> DRIVEABILITY - NGC - Diagnostic Tests >> P0442-EVAP System Medium Leak; P0455-EVAP System Large Leak (Gas - NGC) >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2004 Dodge Pickup and 2004 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures.
  1. Check for any related TSBs before continuing.
    NOTE: Since a hot vehicle can conceal a leak, it is best to perform this test at room temperature.
    NOTE: A loose gas cap could have caused this DTC to set. Make sure gas cap is tight and in good condition. Ensure the gas cap meets OEM specifications.

    Ignition on, engine not running.

    With the DRBIII®, read DTCs and record the related Freeze Frame data.

    Is the Good Trip Counter displayed and equal to zero?

    1. Yes --> Go To 2
    2. No --> Refer to the SYMPTOM: INTERMITTENT CONDITION  Symptom (Diagnostic Procedure).

      Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 6 .

  2. Perform a visual and physical inspection of the entire Evaporative Emission system.

    Check for the follow conditions:

    • Holes or cracks
    • Loose seal points
    • Evidence of damaged components
    • Incorrect routing of hoses and tubes
    • Fuel Cap gasket seal

    Were any of the above conditions found?

    1. Yes --> Repair as necessary.

      Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 6 .

    2. No --> Go To 3
  3. To continue testing you will need Miller Tool #8404A Evaporative Emission Leak Detector (EELD).
    WARNING: Keep lit cigarettes, sparks, flames, and other ignition sources away from the test area to prevent the ignition of explosive gases. Keep the test area well ventilated.
    NOTE: The fuel tank should have between 20% and 80% of fuel tank capacity to properly test the Evap system.

    Connect the red power lead of the EELD to the battery positive terminal and the black ground lead to battery negative terminal.

    NOTE: See Charts and Graph support material EELD Calibration Setup for an example.

    Block the vent hose of the canister if using the service port.

    Connect shop air to the EELD.

    Set the smoke/air control switch to AIR.

    Insert the tester's AIR supply tip (clear hose) into the appropriate calibration orifice on the tester's control panel (based on DTC leak size).

    Press the remote smoke/air start button.

    Position the red flag on the air flow meter so it is aligned with the indicator ball.

    When the calibration is complete, release the remote button. The EELD flow meter is now calibrated in liters per minute to the size leak indicated by the DTC set in the PCM.

    Install the service port adapter #8404-14 on the vehicle's service port and block the vent hose of the EVAP Canister (if equipped) or install the #8404-ADP service adaptor into the filter line.

    Connect the Air supply hose from the EELD to the service port (if equipped) or to the #8404-ADP adapter.

    Press the remote button to activate AIR flow.

    NOTE: Larger volume fuel tanks, lower fuel levels or if the vehicle is equipped with a Flow Management Valve may indicate high flow and will require 4 to 5 minutes to fill.

    Compare the flow meter indicator ball reading to the red flag.

    ABOVE the red flag indicates a leak present.

    BELOW the red flag indicates a sealed system.

    Is the indicator ball above the red flag?

    1. Yes --> Go To 4
    2. No --> Refer to the SYMPTOM: INTERMITTENT CONDITION  Symptom (Diagnostic Procedure).

      Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 6 .

  4. NOTE: A thorough visual inspection of the Evap system hoses, tubes, and connections may save time in your diagnosis. Look for any physical damage or signs of wetness at connections. The strong smell of fuel vapors may aid diagnosis also.
    NOTE: The flow meter indicator ball will not move in the smoke mode.
    NOTE: Ensure that smoke has filled the EVAP system by continuing to press the remote smoke/air start button, remove the vehicle fuel cap, and wait for the smoke to exit. Once smoke is indicated reinstall the fuel cap.
    NOTE: For optimal performance, introduce smoke into the system for an additional 60 seconds; continue introducing smoke at 15 second intervals, as necessary.
    NOTE: Carefully inspect the vent side of the EVAP Canister. Due to the filtering system in the canister the smoke may not be as thick. Introducing smoke into the filtered side of the canister may assist in locating the leak.
    NOTE: After disconnecting the Evap Purge Solenoid vacuum connections, inspect the lines and solenoid for any signs of contamination from the EVAP Canister. This may indicate a faulty rollover valve. Replace/repair as necessary.
  5. To continue testing, you will need Miller Tool #8404A Evaporative Emissions Leak Detector (EELD).

    Remove the Air supply hose from the service port (if equipped) or from the #8404-ADP adapter.

    Connect the SMOKE supply tip (black hose) to the service port (if equipped) or to the #8404-ADP adapter.

    Set the smoke/air control switch to SMOKE.

    Press the remote smoke/air start button.

    While still holding the remote smoke/air start button, use the white light (#8404-CLL) to follow the EVAP system path, and look for the source of the leak indicated by exiting smoke.

    If a leak is concealed from view (i.e., top of fuel tank), release the remote smoke/air start button, and use the ultraviolet (UV) black light #8404-UVL and the yellow goggles 8404-20 to look for residual traces of dye that is left behind by the smoke. The exiting smoke deposits a residual fluid that is either bright green or bright yellow in color when viewed with a UV light.

    Was a leak found?

    1. Yes --> Repair or replace the leaking component as necessary.

      Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 6 .

    2. No --> Go To 5
  6. Turn the ignition off.

    Disconnect the vacuum hoses at the Evap Purge Solenoid.

    Using a hand vacuum pump, apply 10 in Hg to the "CAN" of the EVAP Purge Solenoid.

    NOTE: Monitor the vacuum gauge for at least 15 seconds.

    Does the EVAP Purge Solenoid hold vacuum?

    1. Yes --> Test Complete.
    2. No --> Replace the Evap Purge Solenoid.

      Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 6 .