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Home >> Mazda >> 2003 >> B2300 Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0442: EVAP Monitor >> Diagnostic Procedures
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Diagnostic Procedures

  1. If QUICK TEST was not performed, go to QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
  2. Visually Inspect Components For Small Leaks -  Verify fuel cap is installed. DO NOT tighten cap or check for correct installation at this time. Verify EVAP Canister Vent (CV) solenoid is properly seated on EVAP canister. Visually inspect for cut or loose connections to fuel vapor hoses/tubes in the following locations:
    • EVAP canister to EVAP canister purge valve.
    • EVAP canister to evaporative emission valve assembly.
    • Evaporative emission valve tube assembly to fuel tank.

    Check fuel filler pipe for damage. If a problem is found, repair or install a new component as necessary. After repair, go to step  10 . If a problem is not found, go to next step.

  3. Check For Small System Leaks From EVAP Test Port -  Connect EVAP System Leak Tester to EVAP test port. Perform EVAP System Leak Test. Refer to FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - B2300, B3000, B4000 & TRIBUTE article. If EVAP System Leak Test passes, go to next step. If EVAP System Leak Test does not pass, go to step  5 .
  4. Check For Small Leaks At Fuel Filler Cap & Evaporative Test Port -  Connect EVAP System Leak Tester to fuel filler pipe. Using scan tool, with KOEO, select DIAGNOSTIC DATA LINK. Select PCM. Select ACTIVE COMMAND MODES. Select OUTPUT TEST MODE. Close EVAP CV solenoid using EVAPCV PID. Pressurize EVAP system to 14 in. H2O (3.48 kPa). Using ultrasonic leak detector, check for leaks around fuel filler cap and evaporative test port. If a leak is not detected, remove leak tester. Install fuel filler cap. Go to step  11 . If a leak is detected, repair or install NEW component as necessary. After repair, go to step  9 .
  5. Visually Inspect Fuel Filler Cap -  Visually inspect fuel filler cap for damage. If fuel filler cap is damaged, install a NEW fuel cap. After repair, go to step  10 . If fuel filler cap is not damaged, go to next step.
  6. Check For Small Leak With Tester Set At Fill Position -  Using scan tool, with KOEO, select DIAGNOSTIC DATA LINK. Select PCM. Select ACTIVE COMMAND MODES. Select OUTPUT TEST MODE. Close EVAP CV solenoid using EVAPCV PID. Pressurize EVAP system to 14 in. H2O (3.48 kPa). If pressure holds between 13.80-14.20 in. H2O (3.43-3.53 kPa), go to next step. If pressure does not hold between 13.80-14.20 in. H2O (3.43-3.53 kPa), go to step  8 .
  7. Check For Leaks In Complete EVAP System -  Verify EVAP CV solenoid is closed. Verify system is pressurized to 14 in. H2O (3.48 kPa). Using the ultrasonic leak detector, check the following EVAP system locations:
    • EVAP return tube to EVAP canister purge valve.
    • EVAP canister purge valve to EVAP canister vent solenoid assembly.
    • EVAP canister vent solenoid assembly to fuel tank.
    • Fuel filler cap to fuel filler pipe.
    If a leak is detected, repair or install NEW component as necessary. After repair, go to step  10 . If a leak is not detected, discontinue pressurizing system. Go to next step.
  8. Check For Small Leak From EVAP Return Tube To EVAP Canister -  Disconnect fuel tank vapor tube at fuel vapor tee and plug opening in tee. With KOEO, close EVAP CV solenoid by accessing OUTPUT TEST MODE. Pressurize EVAP system to 14 in. H2O (3.48 kPa). Using ultrasonic leak detector, check EVAP system from intake manifold to EVAP CV solenoid. If a leak is detected, repair or install NEW component as necessary. After repair, go to step  10 . If a leak is not detected, discontinue pressurizing system. Open EVAP CV solenoid. Go to next step.
  9. Check For Small Leak Between Fuel Tank Vapor Tube & Fuel Tank Filler Pipe -  Transfer plug from fuel vapor tee to fuel tank vapor tube. Pressurize EVAP system to 14 in. H2O (3.48 kPa). Using ultrasonic leak detector, check fuel tank vapor tube to fuel tank for leaks. Check fuel tank for leaks. Check Fuel Tank Pressure (FTP) sensor, fuel tank vapor tube and fuel filler pipe. If a leak is detected, repair or install NEW component as necessary. After repair, go to next step. If a leak is not detected, reconnect fuel vapor tube to fuel vapor tee. Go to step  11 .
  10. EVAP System Leak Test -  Connect all disconnected connectors and hoses. Perform EVAP System Leak Test. Refer to FUEL EVAPORATIVE SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - B2300, B3000, B4000 & TRIBUTE article. If EVAP System Leak Test passes, go to step  12 to verify repair. If EVAP System Leak Test does not pass, locate and repair leak. Repeat this step.
  11. Drive Cycle -  Reconnect all connectors. Using scan tool, clear DTC from PCM memory. Perform EVAP RUNNING LOSS SYSTEM REPAIR VERIFICATION DRIVE CYCLE  in MONITOR REPAIR VERIFICATION DRIVE CYCLES under DRIVE CYCLE PROCEDURES. Using scan tool, retrieve DTCs. If same DTC is not present, go to next step. If same DTC is present, replace faulty PCM. After repair, go to next step.
  12. Verify Trouble Shooting Of DTCs Completed -  Perform QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If any DTC is present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no DTCs are set, trouble shooting is complete.
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