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Home >> Mazda >> 2003 >> MPV ES >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0446: EVAP System Vent Control - Malfunction >> Diagnostic Procedures
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Diagnostic Procedures

  1. Record freeze frame data. Check for service bulletins and on-line information. Repair as necessary. After repair, go to next step.

  2. Check EVAP System Leak Detection Pump Circuit For Short To Power -  Turn ignition on, engine off. Disconnect EVAP system leak detection pump 4-pin harness connector. Measure voltage between ground and EVAP system leak detection pump 4-pin harness connector terminal "D" (Pink/Blue wire). See Fig 1. If battery voltage is not present, go to next step. If battery voltage is present, repair short to power on Pink/Blue wire between EVAP system leak detection pump 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 43. After repair, go to step  4.
    Fig 1: Identifying EVAP System Leak Detection Pump 4-Pin Harness Connector Terminals
    G00159015Courtesy of MAZDA MOTORS CORP.
  3. Inspect COV (EVAP System Leak Detection Pump) -  Check COV in EVAP leak detection pump. Perform EVAP system leak detection pump inspection. See EVAPORATIVE SYSTEM LEAK INSPECTION USING LEAK TESTER under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If COV is okay, go to next step. If COV is faulty, replace EVAP system leak detection pump. After repair, go to next step.
  4. Verify Trouble Shooting Of DTC P0446 Completed -  Reconnect all disconnected connectors. Turn ignition on, engine off. Using scan tool, clear DTC. See CLEARING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. Turn ignition off. Perform MODE 6 - EVAP SYSTEM REPAIR VERIFICATION DRIVE MODE  under DRIVE MODES. Recheck DTCs. If DTC P0446 is present, replace PCM. After repair, go to next step. If DTC P0446 is not present, go to next step.
  5. Verify After Repair Procedure -  Using scan tool, perform After Repair Procedure. See AFTER REPAIR PROCEDURE . If no other DTCs are present, testing is complete. If any other DTC is present, go to applicable test and repair.
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