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DTC P0456: EVAP System Malfunction - Small Leak Detected: Testing

NOTE: Record freeze frame PID data. Check for service bulletins and on-line information.
  1. Check for DTCs. If any DTCs are present, repair those DTCs first. If other DTCs are not present, go to next step.
  2. Perform EVAP SYSTEM TEST. See SYSTEM & COMPONENT TESTING - MIATA, MILLENIA, MPV, PROTEGE & 626 article. If system fails, go to next step. If system passes, problem is intermittent. Check purge solenoid valve and CDCV circuit.
  3. Using Ultrasonic leak tester, check for leaks at following components:
    • Charcoal canister
    • Catch tank
    • Fuel filler cap
    • EVAP hoses and pipes
    • Fuel tank

    If leaks are not present, go to next step. If leaks are present, repair leak or replace necessary part and go to step  8 .

  4. Disconnect purge solenoid valve vacuum tube. Connect vacuum pump to purge solenoid valve. Apply vacuum and wait 5 seconds. If vacuum holds. go to next step. If vacuum does not hold, replace purge solenoid valve and go to step  8 .
  5. Connect all disconnected hoses and connectors. Place clamp on CDCV hose between CDCV and air filter. Using EVAP system tester, check for leaks. If problem is present, go to step  8 . If problem is not present, go to next step.
  6. Remove clamp. Using EVAP system tester, check for leaks. If problem is present, replace CDCV and go to step  9 . If problem is not present, go to step  9 .
  7. Remove and inspect fuel tank for leaks or damage at fuel pump. If okay, go to next step. If any leaks or damage is present, repair or replace fuel tank or seal ring.
  8. Connect all disconnected hoses and connectors. Using EVAP system tester, check for leaks. Perform WHOLE SYSTEM TEST. See SYSTEM & COMPONENT TESTING - MIATA, MILLENIA, MPV, PROTEGE & 626 article.
  9. Turn ignition on. Using scan tool access ECT and FTL V PIDs. See EVAP TEST REQUIREMENTS  table under DTC P0442: EVAP SYSTEM MALFUNCTION - SMALL LEAK DETECTED. If all readings are within specifications, go to next step. If any readings are not within specifications, take action necessary (e.g., cool down engine). Repeat this step.
  10. Using scan tool, Erase DTC. See CLEARING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. Run engine at 3500 RPM for 3 minutes then run at idle for 6 minutes. Verify TEST #10:23:00 in DIAGNOSTIC MONITORING TEST RESULTS. If zero or 65535 is not indicated, go to next step. If zero or 65535 is indicated, monitoring was not implemented. repeat step  8 .
  11. Using scan tool, verify TEST #10:23:00 in DIAGNOSTIC MONITORING TEST RESULTS. If test does not exceed MAX value, go to next step. If test exceeds MAX value, replace PCM then go to next step.
  12. Perform after repair procedure. See AFTER REPAIR PROCEDURE  . If DTC is not present, testing is complete. If any DTC is present, go to appropriate test for diagnosis and repair.
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