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Test Z: Intermittent: Testing

    NOTE: For additional testing information, see DIAGNOSTIC AIDS .
    NOTE: Typical PID values will be compared to actual PID values many times during the following test procedures. Always keep typical PID values available for referencing.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 1) to step 10). No test procedures have been omitted.

  1. 1) Determine Intermittent Test Procedure
    Road test vehicle and use the typical PID values in PIN VOLTAGE/PID VALUE TABLES to determine which input or output is not within specification. See VILLAGER 3.3L A/T (4F20E) under PIN VOLTAGE/PID VALUE TABLES under PID DEFINITIONS & PIN VOLTAGE/PID VALUES in PIN VOLTAGE/PID VALUE CHARTS - TRUCKS article. Using results from road test, choose an intermittent diagnostic procedure from INTERMITTENT TEST PRIORITIZING  table. Perform appropriate test listed in table, in order of importance; i.e, 1, 2, then 3 (if applicable):
    • For Input Test, go to step  10).
    • For Output Test, go to step  20).
    • For Water Soak Test, go to step  30).
    • For Road Test, go to step  40).
      INTERMITTENT TEST PRIORITIZING

      PID PCM Terminal No. Input Test Output Test Water Soak Road Test
      ACR 12 N/A 1 N/A 2
      AC SW 21 1 N/A 3 2
      LFAN 34 N/A 1 N/A 2
      HFAN 32 N/A 1 N/A 2
      IAT 61 1 N/A 2 3
      IDLE SW 26 1 N/A 3 2
      VST 2 1 N/A 3 2
      MAF 52 1 N/A 2 3
      O2S11 48 1 N/A 3 2
      PSP_SW 35 1 N/A 3 2
      TP 23 1 N/A 3 2
      VSS 27 1 N/A 3 2

      Ensure proper PID data and/or possible cause information is available and refer to INTERMITTENT TEST PRIORITIZING  table to identify proper test procedure.

    2. NOTE: Typical PID values will be compared to actual PID values many times during the following test procedures. Always keep typical PID values available for referencing.

  2. 10) KOEO Input Test
    Turn ignition off. Connect scan tool to DLC. Using scan tool, access PIDs from PID/DATA MONITOR & RECORD menu based on information from SYSTEM TEST or INTERMITTENT TEST PRIORITIZING table that directed you to this procedure. Turn ignition on. If suspect input device is a switch-type component, turn it on manually. While observing appropriate PID value, wiggle and pull on component wiring and connector. Lightly tap on component. If PID value is within specification and does not abruptly change when wiggled, go to next step. If sudden change occurs in PID value or PID value drops out of range when wiggled, closely inspect each wire and connector for damage and repair as necessary. If after close inspection of wire and connector, fault cannot be located, replace suspect component. If replacement of component does not repair fault, install original component and go to next step.

  3. 11) KOEO Input Test From Component To PCM

    Ensure ignition is on. Continue to monitor PIDs as in previous step. While observing PID value, wiggle and pull on wiring harness between suspect component and PCM. Lightly tap on component. If PID value(s) remain within typical PID value, go to next step. If sudden change occurs in PID value or PID value drops out of specified range, isolate fault and repair as necessary. If fault cannot be located, inspect PCM connector. If PCM connector is okay, replace PCM. If replacement PCM does not repair fault, reinstall original PCM. Return to step  1) and choose another procedure.

  4. 12) KOER Input Test

    Leave ignition on with PIDs accessed. Select PID(s) from area of suspected wiring or component fault. Start engine and allow to idle. While observing PID(s) value, wiggle and pull on component wiring and connector. Lightly tap on component. If PID value(s) remain within typical PID value, go to next step. If sudden change occurs in PID value or PID value drops out of specified range, carefully inspect each wire and connector. If fault cannot be located, replace component. If replacement component does not repair fault, reinstall original component and go to next step.

  5. 13) KOER Input Test From Component To PCM

    Leave engine running at idle speed with PID(s) accessed. While observing PID value(s), wiggle and pull on wiring harness between suspect component and PCM. Lightly tap on component. If PID value(s) remain within typical PID value, fault cannot be identified with this procedure. Return to step  1) and choose another procedure. If sudden change occurs in PID value or PID value drops out of specified range, isolate fault and repair as necessary. If after repair fault cannot be located, replace PCM. If replacement of PCM does not repair fault, reinstall original PCM and return to step 1)  to choose another procedure.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 13) to step 20). No test procedures have been omitted.
    6. NOTE: Some output devices such as fuel injectors or idle air controllers require vehicle to be driven to be checked. In these cases, a road test may be necessary. Go to step  40) to test outputs that cannot be controlled in OUTPUT TEST MODE.
    NOTE: Typical PID values will be compared to actual PID values many times during the following test procedures. Always keep typical PID values available for referencing.

  6. 20) KOEO Output Procedure
    Turn ignition off. Connect scan tool to DLC. Using scan tool, access PIDs from PID/DATA MONITOR & RECORD menu based on information from SYSTEM TEST or INTERMITTENT TEST PRIORITIZING table that directed you to this procedure. Retrieve and record any Continuous Memory DTCs from PCM memory, if any are present, before proceeding with this step. Turn ignition on. Using scan tool, enter OUTPUT TEST MODE. See OUTPUT TEST MODE  under ADDITIONAL SYSTEM FUNCTIONS. Command suspect output device(s) ON. While observing PID value, lightly tap on component. Compare actual PID value(s) to typical PID value(s) specification. If PID values are correct and remain stable, fault might be intermittent. Go to next step. If PID values are incorrect or unstable, replace suspect output device. If replacement of output device does not repair fault, reinstall original component and go to next step.

  7. 21) Output Wiring Test

    Leave ignition on. Using scan tool, continue to monitor PIDs. Command suspect output device(s) ON. Wiggle and pull on wiring harness (VPWR and control circuits) between suspect output device and PCM. Lightly tap on component. Compare actual PID value(s) to typical PID value(s). If PID values are correct and remain stable within one volt, fault cannot be identified with this procedure. Return to step  1) and choose another procedure. If PID value(s) are incorrect or unstable, isolate fault and repair as necessary.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 21) to step 30). No test procedures have been omitted.
    8. NOTE: Typical PID values will be compared to actual PID values many times during the following test procedures. Always keep typical PID values available for referencing.

  8. 30) KOER Water Soak Test
    Connect scan tool to DLC. Using scan tool, access PIDs from PID/DATA MONITOR & RECORD menu based on information from SYSTEM TEST or INTERMITTENT TEST PRIORITIZING table that directed you to this procedure. Start engine and allow to idle. Spray water on suspect component, wiring and connectors. Compare actual PID value(s) to typical HOT IDLE PID value(s) specification. If no engine stumble or sudden change occurs in actual PID value(s) and PID value stays within specified range, go to next step. If engine stumbles or sudden change occurs in PID value or PID value drops out of specified range while spraying water on a component, replace part and verify repair. If replacement part does not repair fault, reinstall original part and go to next step. If engine stumbles or sudden change occurs in PID value or PID value drops out of specified range while spraying water on wiring, check each wire for corrosion, bent or loose terminals and poor connections. If engine stumbles or sudden change occurs in PID value or PID value drops out of specified range while spraying water on a vacuum line, repair as necessary and verify repair.

  9. 31) Water Soak Retest

    With engine running, spray water on spark plugs, spark plug wires, ICM, CKP sensor, CMP sensor and any related relays. Compare actual PID value(s) to typical HOT IDLE PID value(s) specification. If no engine stumble or sudden change occurs in actual PID value(s) and PID value stays within specified range, fault cannot be identified with this procedure. Return to step  1) and choose another procedure. If engine stumbles or sudden change occurs in PID value or PID value drops out of specified range while spraying water on a component, replace part and verify repair. If replacement part does not repair fault, reinstall original part and return to step  1) to choose another procedure. If engine stumbles or sudden change occurs in PID value or PID value drops out of specified range while spraying water on wiring, check each wire for corrosion, bent or loose terminals and poor connections. If engine stumbles or sudden change occurs in PID value or PID value drops out of specified range while spraying water on a vacuum line, repair as necessary and verify repair.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 31) to step 40). No test procedures have been omitted.

  10. 40) Road Test Procedure: KOEO PID Comparison

    This procedure will monitor PIDs and components using scan tool on a road test. An assistant is necessary for some portions of this test. This procedure is performed under 4 different conditions: KOEO, HOT IDLE, 30 MPH and 55 MPH. Turn ignition off. Connect scan tool to DLC. Using scan tool, access PIDs from PID/DATA MONITOR & RECORD menu based on information from SYSTEM TEST or INTERMITTENT TEST PRIORITIZING table that directed you to this procedure. Compare actual PID values to KOEO PID value(s). If KOEO PID values are within specified range, go to next step. If an input device KOEO PID value is out of range, return to step  10). If an output device KOEO PID value is out of range, return to step  20).

  11. 41) Road Test Procedure: HOT IDLE PID Comparison

    Continue to monitor actual PID value(s) as in previous step. Start engine and allow to idle. Ensure engine is at normal operating temperature. Monitor suspect PID values for a sudden change or fluctuating engine speed. Compare actual PID values to HOT IDLE PID value(s). If HOT IDLE PID values are within specified range, go to next step. If an input device HOT IDLE PID value is out of range or drops out and then back into range, return to step  10). If an output device HOT IDLE PID value is out of range or drops out and then back into range, return to step  20).

  12. 42) Road Test Procedure: 30 MPH PID Comparison

    Continue to monitor actual PID value(s) as in previous step. Ensure engine is at normal operating temperature. Turn all electrical accessories off. Secure scan tool and any other diagnostic tools and road test vehicle at a steady 30 MPH. Monitor suspect PID values for a sudden change or fluctuating engine speed. Compare actual PID values to 30 MPH PID value(s). If 30 MPH PID values are within specified range, go to next step. If an input device 30 MPH PID value is out of range or drops out and then back into range, return to step  10). If an output device 30 MPH PID value is out of range or drops out and then back into range, return to step  20).

  13. 43) Road Test Procedure: 55 MPH PID Comparison

    Continue to monitor actual PID value(s) as in previous step. Ensure engine is at normal operating temperature. Turn all electrical accessories off. Secure scan tool and any other diagnostic tools and road test vehicle at a steady 55 MPH. Monitor suspect PID values for a sudden change or fluctuating engine speed. Compare actual PID values to 55 MPH PID value(s). If 55 MPH PID values are within specified range, fault cannot be identified with this procedure. Return to step  1) and choose another procedure. If an input device 55 MPH PID value is out of range or drops out and then back into range, return to step  10). If an output device 55 MPH PID value is out of range or drops out and then back into range, return to step  20).
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