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Home >> Nissan-Datsun >> 2003 >> Sentra Limited >> Repair and Diagnosis >> External Pages >> Different car >> Section 41 (Engine Controls - Self-Diagnostics - Quest) >> Diagnostic Tests >> DTC P1444: EVAP Canister Purge Volume Control Valve >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn ignition off. Disconnect EVAP-CPVCV harness connector. See Figure. Turn ignition on. Measure voltage between ground and EVAP-CPVCV harness connector terminal No. 1 (Black/White wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short circuit and retest system. See WIRING DIAGRAMS article.
  2. Turn ignition off. Disconnect ECM harness connector. See Figure. Check continuity of Green/Black wire between EVAP-CPVCV harness connector terminal No. 2 and ECM harness connector terminal No. 5. See Figure. Also, check circuit for short to ground and short to voltage. Repair circuit as necessary and retest system. If circuit is okay, go to next step.
  3. Check hose connected to EVAP-CSPS for damage and blockage. See Figure. Repair or replace hose as necessary and retest system. If hose is okay, go to next step.
  4. Disconnect EVAP-CSPS harness connector. Inspect connector for water. If water does not exist, go to next step. If water exists, replace EVAP-CSPS and retest system.
    CAUTION: DO NOT apply more than 5.91 in. Hg of vacuum to EVAP-CSPS. Replace EVAP-CSPS if it has been dropped from a height of more than 20" (.5 m) onto a hard surface such as concrete.
    5. CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  5. Reconnect all harness connectors. Remove EVAP-CSPS with its harness connector connected. Turn ignition on. Using a hand vacuum pump, apply 2.76 in. Hg of vacuum to EVAP-CSPS. Measure voltage between ground and ECM terminal No. 62 (Red wire) by backprobing. See Figure. Voltage should be .4-.6 volt. Disconnect vacuum pump. Voltage should be 3.0-3.6 volts. If voltage is as specified, go to next step. If voltage is not as specified, replace EVAP-CSPS and retest system.
  6. Disconnect vacuum hoses from EVAP-CPVCV. See Figure. Disconnect EVAP-CPVCV harness connector. Apply air pressure to port "A" at EVAP-CPVCV. See Figure. Air should not flow from port "B". Using fused jumper wires, apply battery voltage between EVAP-CPVCV terminals (component side). Air should now flow from port "B". If EVAP-CPVCV operates properly, go to next step. If EVAP-CPVCV does not operate properly, replace EVAP-CPVCV.
  7. Disconnect hose from EVAP-CVCV. See Figure. Check hose for damage and blockage. Repair or replace hose as necessary and retest system. If hose is okay, go to next step.
  8. Remove EVAP-CVCV. Check EVAP-CVCV for rust and damage. Rust should not exist in port "B". See Figure. If problem exists, replace EVAP-CVCV. If problem does not exist, go to next step.
  9. Using fused jumper wires, apply battery voltage between EVAP-CVCV terminals (component side). See Figure. Air applied to port "A" should not flow from port "B". Remove jumper wires. Air applied to port "A" should now flow from port "B". If EVAP-CVCV operates as specified, go to step  11. If EVAP-CVCV does not operate as specified, go to next step.
  10. Clean EVAP-CVCV ports with compressed air. Repeat step  9. If EVAP-CVCV now operates as specified, go to next step. If EVAP-CVCV still does not operate as specified, replace EVAP-CVCV and retest system.
  11. Remove EVAP canister with EVAP-CVCV attached. Turn EVAP canister so EVAP-CVCV is pointing down. If water drains out, go to next step. If water does not drain out, go to step  14.
  12. Weigh EVAP canister with EVAP-CVCV attached. Weight should be less than 4 lbs. (1.8 kg). If weight is as specified, go to next step. If weight is not as specified, check EVAP canister for damage. Also, check hose between EVAP canister and water separator for clogging or poor connection. Repair hose or replace EVAP canister as necessary and retest system.
    13. CAUTION: DO NOT disassemble water separator.
  13. Remove water separator located on charcoal canister. Inspect water separator for cracks or blockage. With water separator port "A" plugged, blow air into port "B". See Figure. Air should flow out of port "C". With port "C" plugged, blow air into port "B". Air should flow out of port "A". If operation is as specified, go to next step. If operation is not as specified, replace water separator and retest system.
  14. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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