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DTC P0440 Or P1440: EVAP Control System: Procedure

  1. Ensure fuel cap is original equipment. Remove fuel cap. If air releasing sound was heard while removing fuel cap, go to next step. If air releasing sound was not heard while removing fuel cap, and fuel cap was not tightened properly, clean fuel cap and filler neck with compressed air and reinstall cap. If fuel cap was installed properly, check fuel cap vacuum release valve opening pressure and vacuum. Valve should open when pressure reaches 2.22-2.90 psi (15.3-20.0 kg/cm2 ) and when vacuum reaches 0.98-1.77 in. Hg. Replace fuel cap, if necessary. If fuel cap is okay, go to next step.
  2. Check EVAP system for leaks. See EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. Repair, if necessary. If no leaks are found, check for blockage in water separator. See VACUUM DIAGRAMS article for location. Replace, if necessary. If water separator is okay, check EVAP-CVCV. See DTC P0446: EVAP CANISTER VENT CONTROL VALVE (EVAP-CVCV) . Replace, if necessary. If EVAP-CVCV is okay, go to next step.
  3. Remove EVAP canister with EVAP-CVCV attached. Attempt to drain water from EVAP canister. If water does not drain form EVAP canister, go to next step. If water drains from EVAP canister, weigh EVAP canister with EVAP-CVCV attached. If weight is less than 4.0 lbs. (1.8 kg), go to next step. If weight is more than 4.0 lbs. (1.8 kg), inspect EVAP canister for damage and check hose between water separator and EVAP canister for blockage or leak. Repair hose or replace EVAP canister, if necessary. If EVAP canister and hose are okay go to next step.
  4. Start engine and warm to normal operating temperature. Turn ignition off. Disconnect purge hose from EVAP-CPVCV (on EVAP service port side). See VACUUM DIAGRAMS article for location. Install vacuum gauge to EVAP-CPVCV. Start engine and let idle for at least 80 seconds. Increase engine speed to 2000 RPM, and observe vacuum gauge. If vacuum exists, go to step  6. If vacuum does not exist, go to next step.
  5. Check vacuum hoses to EVAP-CPVCV for blockage or leak. Repair as necessary and retest system. If vacuum hoses are okay, check EVAP-CPVCV. See DTC P0443: EVAP CANISTER PURGE VOLUME CONTROL VALVE (EVAP-CPVCV) . Replace, if necessary. If EVAP-CPVCV is okay, go to next step.
  6. Check AP sensor. See DTC P0105: ABSOLUTE PRESSURE (AP) SENSOR . Replace AP sensor, if necessary. If AP sensor is okay, check MAP/BARO solenoid. See DTC P1105: MANIFOLD ABSOLUTE PRESSURE (MAP)/BAROMETRIC PRESSURE (BARO) SOLENOID . Replace, if necessary. If MAP/BARO solenoid is okay, go to next step.
  7. Check FTT sensor. See DTC P0180: FUEL TANK TEMPERATURE (FTT) SENSOR . Replace, if necessary. If FTT sensor is okay, check EVAP-CSPS. See DTC P0450: EVAP CONTROL SYSTEM PRESSURE SENSOR (EVAP-CSPS) . Replace, if necessary. If EVAP-CSPS is okay, go to next step.
  8. Check for leaks in EVAP purge line. See VACUUM DIAGRAMS article. Repair as necessary. If no leaks are found, clean purge line with compressed air and retest system. Problem may be intermittent. See TESTING PROCEDURE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - INTRODUCTION article.
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