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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:

  1. 1) DTC P0320: Visual Inspection  Check spark plug, plug wires, coils and all connectors for damage, looseness or shorting. Ensure battery is fully charged and in good condition. Repair or replace as necessary. If no faults are found, go to next step.
  2. 2) Check VPWR To PCM  Turn ignition off. Disconnect Idle Air Control (IAC) wiring harness connector. Measure voltage between ground and VPWR terminal of IAC connector. If voltage is less than 1.0 volt, go to next step. If voltage is 1.0 volt or more, go to step 4).
  3. 3) Check EEC Power Relay  Leave ignition off and IAC wiring harness connector disconnected. Disconnect EEC power relay. Measure voltage between ground and VPWR terminal of IAC connector. If voltage is still less than 1.0 volt, replace EEC power relay and repeat QUICK TEST. If voltage is 1.0 volt or more, repair VPWR short to power. Clear PCM memory and repeat QUICK TEST.
  4. 4) Check Secondary Ignition  Using a spark tester, check for spark at all spark plug wires while cranking engine. If consistent spark is present at all spark plug wires, go to step 11). If consistent spark is not present, go to next step.
  5. 5) Install EI Diagnostic Harness  Turn ignition off. Install DI Diagnostic Harness (007-00097) to EEC-V Breakout Box (014-000950). Connect diagnostic harness negative lead to battery negative terminal. Do not connect B+ lead of diagnostic harness. Ensure switch is in the NORMAL position. Use DI overlay on breakout box. Turn ignition on. Set DVOM to DC scale. Measure voltage between test pins J7 (B-) and J5 (ICM PWR) at breakout box. If voltage is 10.0 volts or more, go to next step. If voltage is less than 10.0 volts, repair power circuit to ICM and repeat QUICK TEST.
  6. 6) Check PIP Signal While Cranking  Set voltmeter on AC scale. Crank engine. Measure voltage between test pins J7 (B-) and J15 (PIP) at breakout box. If voltage is 3.0-8.5 volts, go to next step. If voltage is not 3.0-8.5 volts, go to step 12).
  7. 7) Check SPOUT Signal While Cranking  Set voltmeter on AC scale. Crank engine. Measure voltage between test pins J7 (B-) and J10 (SPOUT) at breakout box. If voltage is 3.0-8.5 volts, go to next step. If voltage is not 3.0-8.5 volts, go to step 17).
  8. 8) Check COIL PWR At Coil  Turn ignition off. Disconnect diagnostic harness at coil tee. Turn ignition on. Set DVOM to DC scale. Measure voltage between test pins J7 (B-) and J2 (COIL PWR) at breakout box. If voltage is 10.0 volts or more, go to next step. If voltage is less than 10.0 volts, repair power circuit to ICM and repeat QUICK TEST.
  9. 9) Check For Coil- Signal While Cranking  Turn ignition off. Connect positive lead of diagnostic harness to battery positive terminal. Connect incandescent test light between breakout box test pins J1 (B+) and J3 (COIL-). Crank engine. If test light blinks brightly once every engine revolution, replace coil and repeat QUICK TEST. If test light does not blink as indicated, go to step 26).
  10. 10) Check Secondary Ignition  Using a spark tester, check for spark at all spark plug wires while cranking engine. If consistent spark is present at all spark plug wires, go to next step. If consistent spark is not present, check for fault in spark plugs, spark plug wires, distributor cap or rotor.
  11. 11) Check Spark Plugs  Remove spark plugs. Check spark plug for damage, wear or incorrect gap. Repair or replace if necessary. If no faults are found, go to step 50) of CIRCUIT TEST Z .
  12. 12) Check CMP PWR At CMP Sensor  Turn ignition off. Disconnect diagnostic harness at CMP sensor. Turn ignition on. Set DVOM to DC scale. Measure voltage between test pins J7 (B-) and J22 (CMP PWR) at breakout box. If voltage is 10.0 volts or more, go to next step. If voltage is less than 10.0 volts, repair power circuit to CMP sensor and repeat QUICK TEST.
  13. 13) Check PIP Signal From CMP Sensor While Cranking  Turn diagnostic harness switch to PIP OPEN position. Set voltmeter on AC scale. Crank engine. Measure voltage between test pins J7 (B-) and J34 (PIP A) at breakout box. If voltage is 3.0-8.5 volts, go to next step. If voltage is not 3.0-8.5 volts, check CMP wiring. If no faults are found, replace CMP sensor and repeat QUICK TEST.
  14. 14) Check PIP Signal With ICM Disconnected  Turn ignition off. Turn diagnostic harness switch to NORMAL position. Disconnect diagnostic harness at ICM. Set voltmeter on AC scale. Crank engine. Measure voltage between test pins J7 (B-) and J34 (PIP A) at breakout box. If voltage is 3.0-8.5 volts, replace ICM and repeat QUICK TEST. If voltage is not 3.0-8.5 volts, go to next step.
  15. 15) Check PIP Signal With PCM Disconnected  Turn ignition off. Disconnect PCM. Set voltmeter on AC scale. Crank engine. Measure voltage between test pins J7 (B-) and J34 (PIP A) at breakout box. If voltage is 3.0-8.5 volts, replace PCM and repeat QUICK TEST. If voltage is not 3.0-8.5 volts, go to next step.
  16. 16) Check PIP A Circuit To PCM  Turn ignition off. Disconnect diagnostic harness at CMP sensor. Turn ignition on. Measure voltage between test pins J7 (B-) and J34 (PIP A) at breakout box. If voltage is less than 0.5 volts, repair short to ground in PIP circuit between CMP sensor and PCM or ICM. Clear PCM memory and repeat QUICK TEST. If voltage is 0.5 volts or more, repair short to power in PIP circuit between CMP sensor and PCM or ICM. Clear PCM memory and repeat QUICK TEST.
  17. 17) Check SPOUT Circuit While Cranking  Turn diagnostic harness switch to SPOUT OPEN position. Set voltmeter on AC scale. Crank or start engine. Measure voltage between test pins J7 (B-) and J10 (SPOUT) at breakout box. If voltage is 3.0-8.5 volts, replace ICM and repeat QUICK TEST. If voltage is not 3.0-8.5 volts, go to next step.
  18. 18) Turn ignition off. Disconnect diagnostic harness at ICM. Turn diagnostic harness switch to NORMAL position. Measure voltage between test pins J7 (B-) and J10 (SPOUT) at breakout box. If voltage is less than 0.5 volts, go to step 20). If voltage is 0.5 volts or more, go to next step.
  19. 19) Turn ignition off. Disconnect PCM wiring harness connector. Measure voltage between test pins J7 (B-) and J10 (SPOUT) at breakout box. If voltage is less than 0.5 volts, go to step 22). If voltage is 0.5 volts or more, repair short to power in SPOUT circuit between ICM and PCM. Clear PCM memory and repeat QUICK TEST.
  20. 20) Leave ignition off. Measure resistance between test pins J7 (B-) and J10 (SPOUT) at breakout box. If resistance is less than 10,000 ohms, go to next step. If resistance is 10,000 ohms or more, go to step 22).
  21. 21) Check For SPOUT Short To Ground In Harness  Leave ignition off and PCM disconnected. Measure resistance between test pins J7 (B-) and J10 (SPOUT) at breakout box. If resistance is less than 10,000 ohms, repair SPOUT circuit between ICM and PCM. If resistance is 10,000 ohms or more, go to next step.
  22. 22) Leave ignition off and PCM disconnected. Set voltmeter on AC scale. Crank engine. Measure voltage between test pins J7 (B-) and 49 (PIP) at breakout box. If voltage is 3.0-8.5 volts, go to next step. If voltage is not 3.0-8.5 volts, go to step 26).
  23. 23) Check ICM GND At PCM  Leave ignition off and PCM disconnected. Reconnect ICM to diagnostic connector. Measure resistance between test pins J7 (B-) at breakout box and test pin No. 23 (IGN GND) at PCM connector. If resistance is less than 5 ohms, replace PCM and repeat QUICK TEST. If resistance is 5 ohms or more, go to next step.
  24. 24) Check ICM GND At PCM  Leave ignition off and PCM disconnected. Connect diagnostic harness CMP sensor tee between CMP sensor and wiring harness connector. Measure resistance between test pins J7 (B-) and J35 (IGN GND) at breakout box. If resistance is less than 5 ohms, repair IGN GND circuit between CMP sensor and PCM. If resistance is 5 ohms or more, replace CMP sensor and repeat QUICK TEST.
  25. 25) Check PIP A Signal At CMP Sensor  Turn ignition off. Turn diagnostic harness switch to NORMAL position. Connect diagnostic harness CMP sensor tee between CMP sensor and wiring harness connector. Set voltmeter on AC scale. Crank engine. Measure voltage between test pins J7 (B-) and J34 (PIP A) at breakout box. If voltage is not 3.0-8.5 volts, replace CMP sensor and repeat QUICK TEST. If voltage is 3.0-8.5 volts, repair open in PIP circuit between CMP sensor and PCM.
  26. 26) Check COIL- Circuit  Leave ignition off and PCM disconnected. Disconnect diagnostic harness ICM tee from ICM. Leave ICM connected to wiring harness connector. Disconnect B+ lead of diagnostic harness from battery. Measure resistance between test pins J3 (COIL-) and J4 (ICM COIL-) at breakout box. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in COIL- circuit between ICM and ignition coil. Clear PCM memory and repeat QUICK TEST.
  27. 27) Turn ignition on. Measure voltage between test pins J3 (COIL-) and J7 (B-) at breakout box. If voltage is less than 5.5 volts, go to next step. If voltage is 5.5 volts or more, repair short to power in COIL- circuit between ICM and ignition coil. Clear PCM memory and repeat QUICK TEST.
  28. 28) Turn ignition off. Measure resistance between test pins J3 (COIL-) and J7 (B-) at breakout box. If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair short to power in COIL- circuit between ICM and ignition coil. Clear PCM memory and repeat QUICK TEST.
  29. 29) Leave ignition off. Measure resistance between test pins J7 (B-) and J9 (GND) at breakout box. If resistance is more than 5 ohms, go to next step. If resistance is 5 ohms or less, replace ICM. Clear PCM memory and repeat QUICK TEST.
  30. 30) Leave ignition off. Measure resistance between test pins J7 (B-) and J28 (GND) at breakout box. If resistance is less than 5 ohms, repair open in GND circuit between CMP sensor and ICM. If resistance is 5 ohms or more, replace CMP sensor and repeat QUICK TEST.
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