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Home >> Mazda >> 2002 >> Tribute LX, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 27 (Engine Controls - Self-Diagnostics - 2.5L) >> Diagnostic Tests >> DTC P1450: EVAP Control System Malfunction (Excessive Vacuum) >> Diagnosis & Repair Procedure

Diagnosis & Repair Procedure

WARNING: This page is about a different car, the 2002 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ensure FREEZE FRAME DATA has been recorded. Check for related service bulletins. Repair as necessary and go to next step.
  2. Turn ignition off and on. Using scan tool, check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If DTC P0443 is present, repair that DTC first. DTC P0443: EVAPORATIVE EMISSION SYSTEM PURGE SOLENOID VALVE CIRCUIT MALFUNCTION  . If DTC P0443 is not present, go to next step.
  3. Using scan tool, activate CDCV. If CDCV operation can be heard, go to next step. If CDCV operation can not be heard, check CDCV operation. See SYSTEM & COMPONENT TESTING - MIATA, MILLENIA, MPV, PROTEGE, PROTEGE5 & 626 article. Replace CDCV as necessary and go to step  8 .
  4. Disconnect vacuum hose between intake manifold and purge solenoid valve at purge solenoid valve. Connect vacuum pump to purge solenoid valve. Apply vacuum for a few seconds. If vacuum holds, disconnect vacuum pump, reconnect vacuum hose and go to next step. If vacuum does not hold, replace purge solenoid valve and go to step  8 .
  5. Inspect charcoal canister condition. See SYSTEM & COMPONENT TESTING - MIATA, MILLENIA, MPV, PROTEGE, PROTEGE5 & 626 article. Replace charcoal canister as necessary and go to step  8 . If charcoal canister is okay, go to next step.
  6. Check fuel tank pressure sensor operation. See SYSTEM & COMPONENT TESTING - MIATA, MILLENIA, MPV, PROTEGE, PROTEGE5 & 626 article. Replace fuel tank pressure sensor as necessary and go to step  8 . If fuel tank pressure sensor is okay, go to next step.
  7. Remove air filter from CDCV vent hose. Ensure air filter is not blocked. Replace as necessary and go to next step. If air filter is okay, check for blockage in drain passage and vent hose between CDCV and EVAP canister. Repair or replace as necessary and go to next step.
  8. Turn ignition on. Using scan tool access IAT PID, FTP PID, LOAD PID, VSS PID, FTL PID and BARO PID data. Intake Air Temperature (IAT) should be less than 102°F (38.9°C), Fuel Tank Pressure (FTP) should be -.55-2.9 in. Hg, calculated load (LOAD) should be 15-80 percent, Vehicle Speed Sensor (VSS) should be 25-75 MPH, Fuel Tank Level (FTL) should be 15-85 percent, and atmospheric pressure (BARO) should be more than 22.5 in. Hg. If any PID data is not as specified, allow engine to cool and repeat this step. All PID data must be as specified to perform next step. If all PID data is as specified, go to next step.
  9. Using scan tool, perform EVAP system repair verification drive mode. See DRIVE MODES  under SELF-DIAGNOSTIC SYSTEM. Stop vehicle and access ON BOARD SYSTEM READINESS TESTS menu of GENERIC OBD II FUNCTIONS to check drive mode completion status. If EVAPORATIVE PURGE SYSTEM monitoring complete, go to next step. If EVAPORATIVE PURGE SYSTEM monitoring is not complete, repeat previous step.
  10. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If DTC P1450 is present, replace PCM and go to next step. See REMOVAL, OVERHAUL & INSTALLATION article. On vehicles equipped with immobilizer system, reprogram ignition key identification numbers. See COMPUTER RELEARN PROCEDURES - IMPORT article in GENERAL INFORMATION. If DTC P1450 is not present, go to next step.
  11. Perform DTC confirmation procedure. See DTC CONFIRMATION PROCEDURE  under SELF-DIAGNOSTIC SYSTEM. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If any other DTC is present, go to appropriate test.
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