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Home >> Isuzu >> 2001 >> Rodeo S, 2.2 D, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.2L >> Diagnostic Tests >> DTC P0442: Small Leak Detected In EVAP System, Or DTC P0456: EVAP Control System Very Small Leak Detected >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK  . After performing OBD-II system check, go to next step.
  2. If DTC P0461, P0462 or P0463 is set, repair that DTC first. See 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. Using scan tool, command EVAP canister purge control valve and vent solenoid on and off. Ensure purge valve and vent solenoid make a clicking sound 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. See appropriate chart in PIN VOLTAGE CHARTS article.
  4. 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  7 . If reading is not as specified, go to next step.
  5. 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.
  6. Disconnect battery. Wait at least 20 seconds. Reconnect battery and go to step  4 .
    NOTE: Calibrate EVAP pressure/vacuum gauges before proceeding. See manufacturer's operating instructions.
  7. Install fuel cap. Using scan tool, command EVAP vent solenoid ON (closed). Connect EVAP pressure/vacuum gauge to EVAP service port. Attempt to pressurize 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  14 .
    NOTE: Review temperature variation instructions included with EVAP Diagnostic Station pressure and vacuum gauge operating instructions before proceeding.
  8. Turn ignition on. Using scan tool, command EVAP vent solenoid on (closed). Using EVAP pressure/vacuum gauge, pressurize EVAP system until scan tool value reads 1.47-1.51 volts. Hold pressure on system for 2 minutes. If scan tool reading decreases to less than specified value, go to next step. If scan tool reading stays within specified range, see DIAGNOSTIC AIDS  .
  9. Disconnect fuel tank vapor line and EVAP purge line from EVAP canister. Block canister fitting for fuel tank vapor line. Connect a hand vacuum pump to canister fitting for 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  12 . If vacuum cannot be maintained, go to next step.
  10. Perform a visual and physical inspection of EVAP system. Check for damaged or disconnected fuel tank vapor lines or hoses and EVAP canister. Repair as necessary. Go to step  14 . If no problems were found, go to next step.
  11. Replace EVAP vent solenoid. Go to step  14 .
  12. 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. Go to step  14 . If no problem was found, go to next step.
  13. Using scan tool, command EVAP vent solenoid ON. Using EVAP pressure/vacuum gauge, pressurize EVAP system while locating leak with ultrasonic leak detector. Repair as necessary. Go to next step.
  14. Turn ignition on. Using scan tool, command EVAP vent solenoid ON (closed). Connect EVAP pressure/vacuum gauge to EVAP service port. Attempt to pressurize EVAP system to 15 in. Hg. If 15 in. Hg 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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