1999 Chevrolet Cutaway 7.4 JFACTORY OEM SERVICE PROCEDURE

Diagnostic Procedures

  1. Perform On-Board Diagnostic (OBD) system check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS INTRODUCTION article. After performing OBD system check, go to next step.
  2. Check if DTCs P0442, P0443, P0446, P0449, P0452, P0453, P0462, P0463 or P1441 is set. If any of these DTCs are set, diagnose affected DTCs. If no other DTCs are set, go to next step.
  3. Inspect EVAP system for loose, incorrect, defective or missing fuel tank cap. Check for damaged EVAP system component, check service port for a missing dust cap or for a loose/damaged Schrader valve. Repair as necessary. After repairs, go to step  18. If no problems were found, go to next step.
  4. Ensure battery voltage is 10.5-17.5 volts, fuel level is 3-15 gallons, and engine temperature is less than 70°F (14°C). Zero pressure and vacuum gauges on EVAP Pressure/Purge Diagnostic Station (J-41413). Reinstall fuel cap. Read and Record FAILURE RECORDS data for DTC P0440. Clear DTCs. Using scan tool, command EVAP vent solenoid ON (closed). Connect EVAP pressure/purge diagnostic station to EVAP service port. Using diagnostic station, attempt to pressurize EVAP system to 5 in. H2O. If specified pressure is achieved, fault is not present. If specified pressure is not achieved, go to next step.
  5. Turn ignition off. Remove vacuum source connection from EVAP purge solenoid valve. Connect vacuum gauge directly to vacuum source. DO NOT tee gauge into line. Start and operate engine at idle. If vacuum reading is 12 in. Hg or greater, go to next step. If vacuum reading is not 12 in. Hg or greater, go to step  12.
  6. Turn ignition off. Reconnect vacuum source to EVAP purge solenoid valve. Connect vacuum gauge directly to EVAP purge solenoid valve. Start and operate engine at idle. Using scan tool, command EVAP purge solenoid valve to 100 percent purge. If vacuum gauge reads 12 in. Hg or greater, go to next step. If vacuum gauge does not read 12 in. Hg or greater, go to step  13.
  7. Turn ignition off. Disconnect fuel tank vapor and EVAP purge line from EVAP vapor canister. Plug canister fitting for fuel tank vapor line. Connect a hand-held vacuum pump to EVAP purge line canister fitting. Turn ignition on. Using scan tool, command EVAP vent valve ON (closed). Using vacuum pump, apply 5 in. Hg. If specified vacuum can be obtained and held, go to step  10. If specified vacuum cannot be obtained or held, go to next step.
  8. Leave system connected as in previous step. Disconnect vent line at EVAP vent valve. Plug vent line. Using vacuum pump, apply 5 in. Hg. If specified vacuum can be obtained and held, go to step  14. If specified vacuum cannot be obtained or held, go to next step.
  9. Inspect EVAP vent line from canister to EVAP vent valve for leaks. Replace as necessary. After repairs, go to step  18. If no leaks were found, go to step  15.
  10. Turn ignition off. Remove plug and hand-held vacuum pump. Reconnect EVAP vapor canister purge and tank vent lines. Connect EVAP Pressure/Purge Diagnostic Station (J-14113) to EVAP system service port. Using scan tool, command EVAP vent valve closed. Continuously attempt to pressurize EVAP system. Using Ultrasonic Leak Detector (J-41416), locate and repair EVAP system leak. After repairs, go to step  18. If no leaks were found, go to next step.
  11. Check EVAP system for restrictions. Repair as necessary. After repairs, go to step  18. If no problems were found, go to step  16.
  12. Repair vacuum source to EVAP purge solenoid valve. After repairs, go to step  18.
  13. Replace EVAP purge solenoid valve. After replacing solenoid valve, go to step  18.
  14. Replace EVAP vent valve. After replacing EVAP vent valve, go to step  18.
  15. Replace EVAP canister. After EVAP replacing canister, go to step  18.
  16. Relieve all system pressure. Using scan tool, use PURGE/SEAL function to turn on EVAP purge solenoid valve to varying levels with engine running and quickly seal system with scan tool. While system is sealed, compare EVAP pressure/purge diagnostic station's vacuum gauge to vacuum shown on scan tool from EVAP fuel tank pressure sensor. Allow system to stabilize. If both values indicate the same amount (plus or minus 2 in. Hg) of vacuum in EVAP system, go to step  3. If both values are not the same (plus or minus 2 in. Hg), go to next step.
  17. Replace EVAP pressure sensor. After replacing sensor, go to next step.
  18. Using scan tool, select DTC, CLEAR INFO function. Start and warm engine to normal operating temperature. Operate vehicle within conditions for setting this DTC. If scan tool indicates that this diagnostic test ran and passed, go to next step. If scan tool does not indicate that this diagnostic test ran and passed, go to step  2.
  19. Using scan tool, select CAPTURED INFO function. Check if any undiagnosed DTCs are displayed. Diagnose affected DTCs. If no additional DTCs are displayed, system is okay.
Factory Service Tools

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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.

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