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Home >> Isuzu >> 2000 >> Rodeo LSE, 2.2 D >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.2L >> Diagnostic Trouble Code Identification >> DTC P0440: EVAP System Malfunction >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform On-Board Diagnostic II (OBD-II) system check. See SELF-DIAGNOSTICS - INTRODUCTION article. Go to next step.
  2. Diagnose DTC P0461, P0462 or P0463, if set. See appropriate testing procedure. Go to DTC P0461: FUEL LEVEL SENSOR CIRCUIT RANGE PERFORMANCE , DTC P0462: FUEL LEVEL SENSOR LOW INPUT  or DTC P0463: FUEL LEVEL SENSOR HIGH INPUT  . If specified DTCs are not set, go to next step.
  3. Perform a visual and physical inspection of fuel cap. Replace as necessary. Go to step  20. Retest system. If fuel cap is in good condition and properly installed, go to next step.
  4. Using scan tool, command EVAP canister purge control valve and vent solenoid on and off. Ensure purge valve and vent solenoid make a click when commanded on and off with scan tool. If click is heard, go to next step. If no click is heard, inspect components and verify PCM output signal to each component.
  5. Turn ignition off. Remove fuel cap. Turn ignition on. Using scan tool, read fuel tank pressure value. If reading is 1.51 volts, go to step  8. If reading is not as specified, go to next step.
  6. If battery has been disconnected, perform a visual and physical inspection of EVAP system. Repair as necessary. Record and clear DTCs from memory. Test drive vehicle. Refer to test procedures for any DTC(s) set. If no DTC sets, problem may be an intermittent condition. If battery was not disconnected, go to next step.
  7. Disconnect battery. Wait at least 20 seconds, and reconnect battery. Go to step  5.
    NOTE: Calibrate EVAP pressure/vacuum gauges before proceeding. See manufacturer's operating instructions.
  8. Install fuel cap. Using scan tool, command the EVAP vent solenoid ON (closed). Connect EVAP pressure/vacuum gauge to EVAP service port. Attempt to pressurize the EVAP system to 5 in. H2 O. If 5 in. H2 O pressure can be achieved, go to next step. If 5 in. H2 O pressure cannot be achieved, go to step  10.
  9. If scan tool fuel tank pressure value remains between 1.47-1.51 volts, go to step  12. If pressure cannot be maintained, go to step  11.
  10. Disconnect fuel tank vapor line and EVAP purge line from EVAP canister. Block canister fitting for the fuel tank vapor line. Connect a hand vacuum pump to the canister fitting for the EVAP purge line. Ensure EVAP vent solenoid is still commanded ON (closed). Apply 5 in. Hg to EVAP canister. If vacuum can be maintained, go to step  15. If vacuum cannot be maintained, go to step  14.
  11. Perform a complete visual and physical inspection of EVAP system. Check for restricted fuel tank vapor line, and a restricted EVAP purge line. Repair as necessary. Go to step  20. If no problems are found, go to DIAGNOSTIC AIDS .
  12. Disconnect vacuum line from between throttle body and EVAP canister. Connect hand vacuum to EVAP canister purge valve vacuum source. Apply 10 in. Hg to EVAP canister purge valve. Using scan tool, command EVAP purge valve ON. If vacuum is released, go to next step. If vacuum is not released, go to step  17.
  13. Connect pressure/vacuum gauge to vacuum source line. Start engine and hold speed at 2500 RPM. While observing vacuum gauge, quickly depress accelerator pedal and allow engine to return to idle. If vacuum gauge reads greater than 10 in. Hg when throttle was opened and closed, go to DIAGNOSTIC AIDS . If reading was not as specified, go to step  18.
  14. Perform a visual and physical inspection of EVAP system. Repair any damaged EVAP components as necessary. Retest system. Go to step  20. If EVAP system components are okay, go to step  19.
  15. Perform a visual and physical inspection of EVAP system. Check for missing, damaged or defective gas cap, vapor lines or EVAP purge line. Repair as necessary. Retest system. Go to step  20. If inspection is okay, go to next step.
  16. Using scan tool, command EVAP vent solenoid ON. Attempt to pressurize the EVAP system, while locating leak with ultrasonic leak detector. Repair as necessary. Go to step  20.
  17. Replace EVAP canister purge valve. Go to step  20.
  18. Repair the cause of no source vacuum to EVAP canister purge valve. Go to step  20.
  19. Replace EVAP vent solenoid. Go to step  20.
    NOTE: Review temperature variation instructions included with EVAP Diagnostic Station pressure and vacuum gauge operating instructions before proceeding.
  20. Turn ignition on. Using scan tool, command the EVAP vent solenoid ON (closed). Connect EVAP pressure/vacuum gauge to EVAP service port. Attempt to pressurize the EVAP system to 15 in. H2 O. If 15 in. H2 O pressure can be achieved and held for 2 minutes, system is okay. If pressure cannot be held, go to step  3.
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