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Home >> Chevrolet >> 2003 >> Tracker 2D Utility, 4WD, Automatic >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Engine Control System Self-Diagnostics - 2.5L) >> Diagnostic Tests >> DTC P0455: EVAP System - Leak Detected >> Diagnostic Procedures
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Diagnostic Procedures

WARNING: This page is about a different variant/trim than selected.
  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. Are any EVAP codes set other than a DTC P0442 or a DTC P0455? If yes, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no, go to next step.
  3. Turn ignition on, with engine off. Observe the FTP sensor parameter with a scan tool. Remove the fuel filler cap. Is the fuel tank pressure within 0.0-0.5 in. H2O (0.0-0.9 mm Hg) with the fuel filler cap removed? If yes, go to next step. If no, go to DTC P0451: FUEL TANK PRESSURE SENSOR PERFORMANCE  .
  4. Visually inspect the entire EVAP control system for loose hose connections, damaged or deteriorated hoses, clogged hoses, missing or damaged components, or loose or incorrect fuel filler cap. Was a problem found? If yes, go to step  7 . If no, go to next step.
  5. Turn ignition on, with engine off. Remove fuel cap and install the gas cap adapter. Connect EVAP Pressure/Purge Diagnostic Station (J-41413) to the gas cap adapter. Command the EVAP canister vent valve ON with the scan tool. Pressurize the EVAP system to 15 in. H2O (28 mm Hg) using the diagnostic station. Monitor the pressure using the gauge on the cart. Turn the rotary switch on the diagnostic station to the HOLD position and observe the EVAP pressure gauge. Does the pressure decrease to less than 10 in. H2O (18.6 mm Hg) within 2 minutes? If yes, go to next step. If no, go to step  8 .
  6. With the conditions in the previous step still met, continually attempt to pressurize the EVAP system to 30 in. H2O (56 mm Hg). Locate any leaks in the EVAP system using the Ultrasonic Leak Detector (J-41416). In order to examine the top tank connections, partially lower the fuel tank. Were any leaks found? If yes, go to next step. If no, go to step  8 .
  7. Repair or replace any leaking or faulty EVAP control system components. After repairs, go to step  23 .
  8. Check for any of the following conditions at the EVAP canister purge valve: No manifold vacuum from the intake manifold vacuum port, leaking or damaged vacuum hoses, restricted vacuum hoses or passages. Repair any condition found. Was a repair necessary? If yes, go to step  23 . If no, go to next step.
    9. WARNING: DO NOT breathe the air through the EVAP component tubes or hoses. The fuel vapors inside the EVAP components may cause personal injury.
  9. Turn ignition on, with engine off. Disconnect the vacuum hoses to the EVAP canister purge valve from the intake manifold and from the EVAP canister. Blow air into the vacuum hose that was disconnected from the EVAP canister. Air should not pass through the EVAP canister purge valve and exit from the intake manifold hose. Command the EVAP canister purge valve ON and adjust the duty cycle to 100 percent with the scan tool. Blow air into the vacuum hose that was disconnected from the EVAP canister. Air should pass through the EVAP canister purge valve and exit from the intake manifold hose. Does the EVAP canister purge valve pass both inspections? If yes, go to step  11 . If no, go to next step.
  10. Backprobe the control circuit for the EVAP canister purge valve at the PCM connector with a test light connected to battery voltage. Command the EVAP canister purge valve ON with the scan tool. Adjust the duty cycle from 0-100 percent while monitoring the test light. Does the test light flash and then illuminate fully as the duty cycle reaches 100 percent? If yes, go to step  18 . If no, go to step  22 .
  11. Turn ignition off. Remove EVAP canister vent valve. Blow air into the EVAP canister vent valve port, located on the side that was connected to the EVAP canister air filter. Did the air pass thorough to the other side of the EVAP canister vent valve? If yes, go to next step. If no, go to step  19 .
  12. Connect the electrical connector of the EVAP canister vent valve. Turn ignition on, with engine off. Command the EVAP canister vent valve ON using a scan tool. Blow air into the EVAP canister vent valve port, located on the side that was connected to the EVAP canister air filter. Was the air unable to pass thorough the EVAP canister vent valve? If yes, go to step  14 . If no, go to next step.
  13. Backprobe the control circuit of the EVAP canister vent valve with a test light connected to battery voltage. Command the EVAP canister vent valve ON and OFF with the scan tool. Did the test light illuminate when the valve was commanded ON? If yes, go to step  19 . If no, go to step  22 .
  14. Disconnect the vacuum/vapor hoses from the EVAP canister. Blow air into the tank port of the EVAP canister. There should be no restriction of air flow thorough the canister and out the purge pipe and the air port. Did the EVAP canister pass the test? If yes, go to next step. If no, go to step  18 .
  15. Remove Fuel Tank Pressure (FTP) control valve. Connect a vacuum hose to the canister side port of the FTP control valve. Important There will be some resistance, but air should flow steadily. Blow air into the hose on the FTP control valve. Did the air flow through the valve to the tank port side? If yes, go to next step. If no, go to step  20 .
    16. NOTE: The FTP control valve allows vapor to flow from the fuel tank to the canister when the fuel tank pressure is greater than canister pressure by more than 0.5 psi (3.5 kPa).
  16. Move the vacuum hose to the fuel tank port of the FTP control valve. Blow hard into the hose connected to the tank port side of the FTP control valve. Air should flow easily through the valve and out of the canister port. Did the FTP control valve pass this test? If yes, go to next step. If no, go to step  20 .
  17. Inspect the EVAP canister air filter and hoses for restrictions or blockage. Repair as necessary. Was a repair necessary? If yes, go to step  23 . If no, go to DIAGNOSTIC AIDS  .
  18. Replace EVAP canister. After repairs, go to step  23 .
  19. Replace EVAP canister vent valve. After repairs, go to step  23 .
  20. Replace FTP control valve. After repairs, go to step  23 .
  21. Replace the EVAP canister purge valve. After repairs, go to step  23 .
  22. Replace PCM. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE  under PROGRAMMING. After replacing PCM, go to next step.
  23. Turn ignition off. Remove DOME fuse for 30 seconds. Install DOME fuse. Reset radio clock time. Start engine. Operate vehicle within the Conditions for Running the DTC or until the DTC P0455 diagnostic test has run. See CONDITIONS FOR RUNNING DTC  . Does the DTC run and pass? If yes, go to next step. If no, go to step  2 .
  24. 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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