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Home >> Pontiac >> 2001 >> Aztek Base, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics >> Diagnostic Tests >> DTC P0442: Evaporative Emission Control System - Small Leak Detected >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform powertrain diagnostic system check. See POWERTRAIN DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check, go to next step.
  2. Using scan tool, recheck for DTCs. If DTC P0443 or P0449 is also set, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If DTC P0443 or P0449 is not set, go to next step.
  3. Check EVAP system for loose, missing or damaged service port Schrader valve. Check for loose, incorrect, missing or damaged fuel fill cap, or damaged EVAP canister purge valve. Raise vehicle on hoist. Check EVAP system for disconnected, improperly routed, kinked or damaged EVAP pipes and hoses. Check for damaged EVAP canister vent valve Repair as necessary. After repairs, go to step  6. If no problem is found, go to next step.
  4. Using scan tool, capture and record FREEZE FRAME/FAILURE RECORDS data and clear DTCs. Using scan tool, perform service bay check. If scan tool indicates that service bay test passed, see DIAGNOSTIC AIDS . If scan tool does not indicate that service bay test passed, go to next step.
    5. NOTE: Before testing, zero gauges on EVAP pressure diagnostic station.
  5. Connect Fill Tank Cap Adapter (J-41415-40) to fuel filler neck and fuel filler cap. Connect EVAP Pressure Diagnostic Station (J-41413) to adapter. Turn ignition on, with engine off. Using scan tool, seal EVAP system. Using EVAP diagnostic station, continuously pressurize EVAP system to 15 in. H2O. Using Ultrasonic Leak Detector (J-41416), check for leaks in EVAP system purge pipe, vapor pipe, vent hose, fuel fill pipe/hose, fuel fill cap, EVAP canister, EVAP canister vent valve, EVAP canister purge valve, fuel sender assembly and/or seal, VTP sensor, fill limiter vent valve, pressure relief valve, rollover valves, permanent EVAP pipes, and/or fuel tank. Repair as necessary. After repairs, go to next step. If no problem is found, see DIAGNOSTIC AIDS .
  6. Turn ignition on, with engine off. Using scan tool, perform Service Bay Check. If scan tool indicates that service bay check passed, go to next step. If scan tool does not indicate that service bay check passed, go to step  2.
  7. Using scan tool, observe the stored information and CAPTURE INFO. If scan tool displays any undiagnosed DTCs, diagnose affected DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are displayed, system is okay.
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