Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Mazda MPV and 2002 Mazda MPV. However, it is still accessible from the selected car via links, so may be relevant.

Record freeze frame data. Check for service bulletins and on-line information. Repair as necessary. After repair, go to next step.
Verify Related Pending Code Or Stored DTCs - Turn ignition on, engine off. Check for related DTCs other than P0456. If other DTCs are not present, go to next step. If any other DTCs are present, repair those DTCs first. Refer to DIAGNOSTIC TROUBLE CODE IDENTIFICATION .
Classify Intermittent Concern Or Continuous Concern Perform EVAP system leak 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 system test result failed (Red light on), go to next step. If system test result passed (Green light on), problem is intermittent. Check purge solenoid valve and EVAP system leak detection pump circuit for intermittent concern. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
Locate Leak Point - Using Ultrasonic leak tester, check for leaks at following components:
- Charcoal canister.
- Catch tank.
- Fuel filler cap.
- EVAP hoses and pipes.
- Fuel tank.
If no leaks are present, go to next step. If leaks are present, repair leak or replace part as necessary. After repair, go to step 9.
Inspect Purge Solenoid Valve - Check purge solenoid valve. See FUEL EVAPORATIVE SYSTEM (MPV) under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If purge solenoid valve is not stuck closed, go to next step. If purge solenoid valve is stuck closed, replace purge solenoid valve. After repair, go to step 9.
Inspect EVAP System Leak Detection Pump - Connect all disconnected hoses and connectors. Place clamp on hose between EVAP system leak detection pump and air filter. Perform EVAP system leak 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 test result passed (Green light on), go to next step. If test result failed (Red light on), go to step 8.
Confirm EVAP System Leak Detection Pump Leakage - Remove clamp. Perform EVAP system leak 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 test result passed (Green light on), go to next step. If test result failed (Red light on), replace EVAP system leak detection pump. After repair, go to step 9.
Inspect Fuel Pump Unit Installation - Remove fuel tank. Check for damage, leaks or incorrectly installed fuel pump. If okay, go to next step. If any leaks or damage are present, repair or replace fuel tank or leaks as necessary. After repair, go to next step.
Perform Leak Inspection - Connect all disconnected hoses and connectors. Perform EVAP system leak 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 test result passed (Green light on), go to next step. If test result failed (Red light on), leak is still present. Locate and repair leak. After repair, go to next step.
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.