Diagnostic Procedure

2004 Nissan-Datsun Altima S, AutomaticSECTION Diagnostic Procedure
  1. CHECK FUEL FILLER CAP DESIGN 
    1. Turn ignition switch OFF.
    2. Check for genuine NISSAN fuel filler cap design.

    OK or NG

    1. OK : GO TO 2.
    2. NG : Replace with genuine NISSAN fuel filler cap.
      Fig 1: Identifying NISSAN Fuel Filler Cap
      G02884521Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK FUEL FILLER CAP INSTALLATION 

    Check that the cap is tightened properly by rotating the cap clockwise.

    OK or NG

    1. OK : GO TO 3.
    2. NG :
      1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
      2. Retighten until reteaching sound is heard.
  3. CHECK FUEL FILLER CAP FUNCTION 

    Check for air releasing sound while opening the fuel filler cap.

    OK or NG

    1. OK : GO TO  5.
    2. NG : GO TO 4.
  4. CHECK FUEL TANK VACUUM RELIEF VALVE 

    Refer to "FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP) ".

    OK or NG

    1. OK : GO TO 5.
    2. NG : Replace fuel filler cap with a genuine one.
  5. CHECK EVAP PURGE LINE 

    Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks, improper connection or disconnection.

    Refer to "EVAPORATIVE EMISSION SYSTEM ".

    OK or NG

    1. OK : GO TO 6.
    2. NG : Repair or reconnect the hose.
  6. CLEAN EVAP PURGE LINE 

    Clean EVAP purge line (pipe and rubber tube) using air blower.

    1. : GO TO 7.
  7. CHECK EVAP CANISTER VENT CONTROL VALVE 

    Check the following.

    OK or NG

    1. OK : GO TO 8.
    2. NG : Repair or replace EVAP canister vent control valve and O-ring.
  8. INSTALL THE PRESSURE PUMP 

    To locate the EVAP leak, install EVAP service port adapter and pressure pump to EVAP service port securely.

    NOTE: Improper installation of the EVAP service port adapter to the EVAP service port may cause leaking.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.