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Home >> Cadillac >> 2002 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 91 (Engine Controls Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P0442: EVAP Control System - Small Leak Detected >> Diagnostic Procedures
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Diagnostic Procedures

WARNING: This page is about a different car, the 2002 Pontiac Sunfire, 2002 Pontiac Grand Am, 2002 Oldsmobile Alero, and 2002 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
  1. Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS  under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
  2. Does scan tool indicate that DTC P0446, P0452, P0453, P0461, P0462, P0463 or P1441 is also set? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, go to next step.
  3. Inspect EVAP system for the following conditions:
    • Loose, missing, or damaged service port Schrader valve.
    • Loose, incorrect, missing, or damaged fuel fill cap.
    • Damaged EVAP canister purge valve.

    Raise vehicle on hoist. Inspect EVAP system for the following conditions:

    • Disconnected, improperly routed, kinked, or damaged EVAP pipes and hoses.
    • Damaged EVAP canister vent valve or EVAP canister.

    Did you find and correct the condition? If yes, go to step  6. If no, go to next step.

    4. NOTE: The following steps require EVAP Pressure/Purge Diagnostic Station (J-41413), and Fuel Tank Cap Adapter (J-41415-40).
  4. Always zero EVAP pressure and vacuum (in. H2O) gauges on EVAP pressure/purge diagnostic station before proceeding with diagnosis. Install fuel tank cap adapter. Connect EVAP pressure/purge diagnostic station and fuel tank cap to fuel tank cap adapter. Turn ignition on, engine off. Using scan tool, DTCs from PCM. Command EVAP vent valve on using scan tool. Pressurize EVAP system to 15 in. H2O with EVAP pressure/purge diagnostic station. Place control knob on EVAP pressure/purge diagnostic station to OFF/HOLD position. Monitor EVAP system pressure on EVAP pressure/purge diagnostic station for 5 minutes. Does the EVAP system pressure remain constant? If yes, see DIAGNOSTIC AIDS . If no, go to next step.
    5. NOTE: It may be necessary to partially lower fuel tank to inspect components located in upper portion of the tank.
  5. With the J-41416, apply 15 in. H2O pressure. Inspect for leaks in the EVAP system purge pipe, EVAP vapor pipe, EVAP vent hose/pipe, fuel fill pipe/hose, fuel fill cap, EVAP canister, canister vent valve, canister purge valve, fuel sender assembly and/or seal, FTP sensor seal, fill limiter vent valve, pressure relief valve, rollover valves, and fuel tank. Did you find and repair the condition? If yes, go to next step. If no, go to DIAGNOSTIC AIDS .
  6. Turn ignition on, engine off. Command EVAP vent valve on using scan tool. Pressurize EVAP system to 15 in. H2O using EVAP pressure/purge diagnostic station. Place control knob on EVAP pressure/purge diagnostic station to OFF/HOLD position. Monitor EVAP system pressure on EVAP pressure/purge diagnostic station for 5 seconds. Does the EVAP system pressure remain constant? If yes, go to next step. If no, go to step  2.
  7. With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? If yes, see DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no, system is okay.
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