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Diagnostic Aids

Perform this test when instructed during QUICK TEST  or if directed by other test procedures. This test is used to diagnose the following:

Fig 1: EVAP Components Using Purge Flow System
G95I12607
Fig 2: EVAP Components Using Vapor Management System
G95D27220
Fig 3: CANP Solenoid Test Circuit & Connector Terminals
G95I35996
Fig 4: Purge Flow Test Circuit & Connector Terminals
G95A35998
  1. 1) DTC P0443: Check VPWR Circuit Voltage  Disconnect Canister Purge (CANP) solenoid or Vapor Management Valve (VMV) wiring harness connector. Turn ignition on. Measure voltage between VPWR terminal of CANP solenoid or VMV wiring harness connector and battery ground. If voltage is 10.5 volts or more, go to next step. If voltage is less than 10.5 volts, repair open in VPWR circuit and repeat QUICK TEST .
  2. 2) Check Component Resistance  Turn ignition off. Leave CANP or VMV wiring harness connector disconnected. Measure resistance between CANP solenoid or VMV terminals. For CANP solenoid, if resistance is 30-90 ohms, go to next step. For VMV, if resistance is 30-36 ohms, go to step 4). If resistance is not as specified, replace CANP solenoid or VMV. Clear PCM memory and repeat QUICK TEST .
  3. 3) Check CANP Solenoid For Internal Short  Turn ignition off. Leave wiring harness connector disconnected. Measure resistance between each solenoid terminal and CANP solenoid housing. If each resistance measurement is more than 90 ohms, CANP solenoid is okay. Go to next step. If resistance is not as specified, replace CANP solenoid. Clear PCM memory, repeat QUICK TEST .
  4. 4) Check VMV Circuit Continuity  Leave ignition off and CANP or VMV wiring harness connector disconnected. Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Measure resistance as follows:
    • For CANP solenoid, between test pin No. 67 at breakout box and EVAP CANP terminal of CANP solenoid wiring harness connector.
    • For VMV, between test pin No. 56 at breakout box and VMV terminal of VMV wiring harness connector.

    If resistance is less than 5 ohms, go to next step. If resistance 5 ohms or more, repair open circuit and repeat QUICK TEST .

  5. 5) Check Circuit For Short To PWR GND  Leave ignition off. Disconnect scan tester from DLC (if applicable). Measure resistance between test pin No. 67 (CANP solenoid) or 56 (VMV) and test pins No. 24 and 103. If each resistance is more than 10,000 ohms, replace PCM and repeat QUICK TEST . If resistance is 10,000 ohms or less, repair EVAP CANP/VMV circuit short to PWR GND circuit. Clear PCM memory and repeat QUICK TEST .
  6. 6) Continuous Memory DTC P1443  This DTC can set by Idle Air Control (IAC) valve speed error during vehicle operation. If Continuous Memory DTC P1507 is also present, go to CIRCUIT TEST KE, step 30). Connect scan tester to Data Link Connector (DLC). Turn ignition on. Using scan tester, access IAC PID, TP PID and RPM PID. Turn all accessories off. Start engine and allow to idle. IAC duty cycle should be 20-45%. Observe IAC PID and RPM PID for indication of fault while shaking and bending IAC valve wiring harness and connector. A fault will be indicated by sudden increase of engine speed and decrease in IAC duty cycle. If fault indicated, isolate/repair as necessary. If no fault go to step 10).
  7. 7) Check Purge Flow Sensor (PFS)  Connect scan tester to Data Link Connector (DLC). Start engine and allow to idle. Disconnect PFS wiring harness connector. Inspect connector for damage and repair if necessary. Using scan tester, access PF PID. If voltage fluctuates about 0.9-1.1 volts, go to step 11). If voltage fluctuates 2.3-2.6 volts, go to step 12). If voltage does not fluctuate as specified, go to next step.
  8. 8) Check PFS Resistance  Turn ignition off. Ensure PFS is about 55-80°F. Measure resistance between PF terminal and VPWR terminal at sensor. Resistance should be less than 160 ohms. Measure resistance between PWR GND terminal and VPWR terminal at sensor. Resistance should be less than 190 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace PFS and repeat QUICK TEST .
  9. 9) Check VPWR Circuit Continuity  Leave ignition off and PFS disconnected. Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Measure resistance between test pins No. 71 and 97 at breakout box and VPWR terminal at PFS. test pins No. 24 and 103. If each resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in VPWR circuit and repeat QUICK TEST .
  10. 10) Check EVAP System  Leave ignition off. Ensure fuel fill cap is installed correctly. Check vacuum hose between fuel tank and carbon canister for faults. Check for carbon canister cracks or damage. Check for fuel tank damage. Check for damaged orifice rollover valve. Repair or replace as necessary. If no faults are found on models equipped with CANP solenoid, go to next step. If no faults are found on models equipped with VMV, go to step 18).
  11. 11) Check CANP Solenoid For Vacuum Leak  Leave ignition off. Disconnect CANP solenoid wiring harness connector. Disconnect hoses from CANP solenoid. Connect vacuum pump to intake manifold side of CANP solenoid. Using vacuum pump, apply 16 in. Hg to solenoid. If vacuum is held for 20 seconds, leave pump connected and go to next step. If vacuum is not held for 20 seconds, replace CANP solenoid and repeat QUICK TEST .
  12. 12) Leave ignition off and CANP solenoid wiring harness connector disconnected. Connect scan tester to DLC. Turn ignition on. Using scan tester, access Output Test Mode and command CANP solenoid on. Using vacuum pump, apply 16 in. Hg to solenoid. When CANP solenoid is commanded on, vacuum should be released. If solenoid does not operates as specified, replace CANP solenoid and repeat QUICK TEST . If solenoid operates as specified, check fuel vapor hoses between carbon canister and CANP solenoid for damage or restriction. Repair as necessary. If no faults are found, go to next step.
  13. 13) Check For Vacuum To CANP Solenoid  Start engine and allow to idle. Check open end of solenoid hose for vacuum. If vacuum is present, leave hose disconnected and go to next step. If vacuum is not present, check vacuum hoses for incorrect routing, cracks or restrictions. Ensure Purge Flow Sensor (PFS) housing is not cracked or damaged. Repair or replace as necessary and repeat QUICK TEST .
  14. 14) Check Purge Flow Sensor (PFS) Leak Down  Turn ignition off. Disconnect PFS wiring harness connector. Plug open end of manifold vacuum hose. Disconnect PFS manifold vacuum hose at manifold. With vacuum pump connected to intake manifold side of CANP solenoid, apply 4 in. Hg to solenoid. If vacuum is held for 2.5 seconds or more, remove vacuum pump and go to next step. If vacuum is not held for 2.5 seconds, replace PFS and repeat QUICK TEST .
  15. 15) Leave PFS wiring harness connector disconnected. Start engine and allow to idle. Check for vacuum at open end of PFS manifold vacuum supply hose. If vacuum is not present, check for a small vacuum leak between PFS and intake manifold. If vacuum is present, check for large vacuum leak between PFS and intake manifold. Repair as necessary. If DTC P1443 is present, go to next step.
  16. 16) Check Component Resistance  Turn ignition off. Leave CANP or VMV wiring harness connector disconnected. Measure resistance between CANP solenoid or VMV terminals. For CANP solenoid, resistance should be 30-90 ohms. For VMV, resistance should be 30-36 ohms. If resistance is as specified, go to next step. If resistance is not as specified, replace CANP solenoid or VMV. Clear PCM memory and repeat QUICK TEST .
  17. 17) Check Circuit For Short To VPWR  Leave ignition off. Disconnect CANP solenoid or VMV wiring harness connector. Disconnect PCM. Measure resistance between test pin No. 67 (CANP solenoid) or 56 (VMV) and test pins No. 71 and 97 at breakout box. If each resistance more than 10,000 ohms, replace PCM, repeat QUICK TEST . If resistance is 10,000 ohms or less, repair EVAP CANP/VMV circuit short to VPWR circuit. Clear PCM memory and repeat QUICK TEST .
  18. 18) Check VMV  Turn ignition off. Reconnect VMV wiring harness connector. Disconnect VMV fuel vapor hose from intake manifold port at VMV. Attach vacuum pump with gauge to intake manifold port at VMV. Using vacuum pump, apply 16 in. Hg to VMV. If vacuum bleeds off immediately, go to next step. If vacuum is not bled off immediately, replace VMV and repeat QUICK TEST .
    Fig 5: VMV Hose Ports
    G95F27222
  19. 19) Check VMV Filter  Turn ignition off. Disconnect vacuum input hose from VMV. Using a vacuum pump, apply 15 in. Hg to VMV. If vacuum is held or bleeds off slowly, go to next step. If vacuum is not held, remove vacuum pump and go to next step.
  20. 20) Check VPWR Circuit Voltage  Turn ignition off. Connect PCM to breakout box. Disconnect VMV wiring harness connector. Turn ignition on. Measure voltage between VPWR terminal of VMV wiring harness connector and battery ground. If voltage is 10.5 volts or more, go to next step. If voltage less than 10.5 volts, repair open in VPWR circuit, repeat QUICK TEST .
  21. 21) Check VMV  Turn ignition off. Ensure PCM is connected to breakout box. Reconnect VMV vacuum input hose. Disconnect fuel vapor to carbon canister hose. Connect vacuum gauge to vacuum port. Start engine and allow to idle for 5 minutes. Vacuum gauge should read zero. Connect jumper wire between test pin No. 56 (VMV) and test pin No. 51 or 103 at breakout box. Vacuum should be about engine manifold vacuum. If vacuum is not as specified, replace VMV and repeat QUICK TEST . If vacuum is as specified, remove vacuum gauge and jumper wire. Go to next step.
  22. 22) Turn ignition off. Disconnect VMV wiring harness connector disconnected. Disconnect upper and lower hose from VMV. Start engine and allow to idle. Check for vacuum at open end of hoses. If vacuum is present, reconnect hoses and go to next step. If vacuum is not present, check hoses for correct routing. Ensure hoses are not damaged or restricted. Repair or replace as necessary.
  23. 23) Turn ignition off. Ensure VMV wiring harness connector is connected. Disconnect vacuum input hose from VMV. Using a vacuum pump, apply 16 in. Hg to VMV. If vacuum bleeds off immediately, go to step 16). If vacuum is not bled off immediately, check hoses for damage or restriction. Repair or replace as necessary and repeat QUICK TEST .
  24. 24) Continuous Memory DTC P1444  Turn ignition off. Connect scan tester to Diagnostic Link Connector (DLC). Turn ignition on. Using scan tester, access PF PID. If PF PID voltage is less than 0.14 volt, go to next step. If voltage is 0.14 volt or more, go to step 27).
  25. 25) Turn ignition off. Disconnect PFS wiring harness connector. Measure resistance between terminal No. 2 and No. 3. See Fig 6. If resistance is less than 25.5 ohms, replace PFS and repeat QUICK TEST . If resistance is 25.5 ohms or more, go to next step.
    Fig 6: PFS Sensor Connector Terminals
    G95I27233
  26. 26) Check PF Circuit For Short To VPWR  Leave ignition off and PFS disconnected. Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Disconnect scan tester (if applicable). Measure resistance between breakout box test pin No. 11 and test pins No. 24 and 103. If each resistance is more than 10,000 ohms, replace PCM and repeat QUICK TEST . If any resistance is 10,000 ohms or less, repair PFS circuit short to PWR GND. Clear PCM memory and repeat QUICK TEST .
  27. 27) Wiggle Test Solenoid & Harness  Turn ignition off. Using scan tester, access PF PID. Observe PF PID for indication of fault while shaking and bending PFS wiring harness and connector. A fault will be indicated by sudden change of voltage. Tap lightly on PFS sensor to simulate road shock. If fault is indicated, isolate and repair as necessary. If no fault is indicated, go to CIRCUIT TEST Z.
  28. 28) Continuous DTC P1445  Turn ignition off. Connect scan tester to Diagnostic Link Connector (DLC). Turn ignition on. Using scan tester, access PF PID. If PF PID voltage is more than 4.8 volts, go to next step. If voltage is 4.8 volts or more, go to step 34).
  29. 29) Turn ignition off. Disconnect PFS wiring harness connector. Allow sensor to cool to room temperature. Measure resistance between terminal No. 1 and No. 2. See Fig 6. If resistance is 40-230 ohms, go to next step. If resistance is not 40-230 ohms, replace PFS sensor and repeat QUICK TEST .
  30. 30) Check PFS Circuit Short To VPWR  Leave PFS sensor disconnected. Turn ignition on. Measure voltage between PF terminal of sensor wiring harness connector and battery ground. If voltage is 10.5 volts or more, go to next step. If voltage is less than 10.5 volts, go to step 32).
  31. 31) Turn ignition off. Leave PFS sensor disconnected. Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Turn ignition on. Measure voltage between breakout box test pin No. 11 and test pins No. 24 and 103. If voltage is greater than 10.5 volts, repair PFS circuit short to VPWR and repeat QUICK TEST . If voltage is 10.5 volts or less, replace PCM and repeat QUICK TEST .
  32. 32) Turn ignition off. Leave PFS sensor disconnected. Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Measure resistance between breakout box test pin No. 11 and PF terminal at sensor wiring harness connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in PF circuit. Clear PCM memory and repeat QUICK TEST .
  33. 33) Leave ignition off and PFS sensor disconnected. Measure resistance between breakout box test pins No. 24 and 103. If resistance is less than 5 ohms, replace PCM and repeat QUICK TEST . If resistance is 5 ohms or more, repair open in PWR GND circuit and repeat QUICK TEST .
  34. 34) Wiggle Test Solenoid & Harness  Turn ignition off. Connect scan tester to DLC. Using scan tester, access PF PID. Observe PF PID for indication of fault while shaking and bending PFS wiring harness and connector. A fault will be indicated by sudden change of voltage. Tap lightly on PFS sensor to simulate road shock. If fault is indicated, isolate and repair as necessary. If no fault is indicated, go to CIRCUIT TEST Z.
  35. 35) Continuous Memory DTC P0443: Check VMV Circuit For Intermittent Failure  Repeat QUICK TEST . If Continuous Memory DTC P0443 is still present, go to next step. If Continuous Memory DTC P0443 is not present, go to step 1).
  36. 36) Wiggle Test Solenoid & Harness  Turn ignition off. Disconnect PCM wiring harness connector. Inspect pins for damage and repair as necessary. Install EEC-V Breakout Box (014-000950), leaving PCM disconnected. Using DVOM, measure resistance between test pin No. 67 (CANP solenoid) or 56 (VMV) and test pins No. 71 and 97. Observe DVOM for indication of fault while shaking and bending VMV wiring harness and connector. A fault will be indicated by resistance measurement of less than 30 ohms or more than 36 ohms (VMV) or 90 ohms (CANP solenoid). Tap lightly on VMV to simulate road shock. If fault is indicated, isolate and repair as necessary. If no fault is indicated, go to CIRCUIT TEST Z.
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