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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. Check VREF Circuit Voltage At TP Sensor

    Turn ignition off. Disconnect TP sensor wiring harness connector. Turn ignition on. Measure voltage between SIG RTN terminal and VREF terminal at wiring harness connector. If voltage is 4-6 volts, go to next step. If voltage is not 4-6 volts, proceed to CIRCUIT TEST C  .

  2. Check Base Timing

    Turn ignition off. Install EI Diagnostic Harness (007-00059) to Breakout Box (014-000950) and ICM. Install coil tee. For 3.8L vehicles, use EI (High Data Rate) 6 overlay. Set diagnostic harness box type switch to "4/6" cylinder position. Connect diagnostic harness negative lead to battery negative terminal. Leave positive lead disconnected. Start engine and check base timing. If base timing is 8-12 degrees BTDC, go to next step. If base timing is not 8-12 degrees BTDC, go to step 9).
    WARNING: Unless otherwise instructed, PCM must not be connected to breakout box when performing ignition system testing.

  3. Check Spark Advance

    Turn ignition off. Ensure SPOUT is connected. Start engine and check timing. If timing is more than 15 degrees BTDC, ignition system is okay and testing is complete. If timing is less than 15 degrees BTDC go to next step.

  4. Check SPOUT Circuit At ICM

    Start engine and allow to idle. Set DVOM on AC scale. Measure voltage between test pins J7 (B-) and J21. If AC voltage is 5 volts or less, go to next step. If voltage is more than 5 volts, replace ICM. Clear PCM memory and repeat QUICK TEST.
  5. Turn ignition off. Push down and hold SPOUT button of diagnostic harness. Start engine and allow to idle. Measure voltage between test pins J7 (B-) and J21. If AC voltage is 5 volts or less, go to next step. If voltage is more than 5 volts, replace ICM. Clear PCM memory and repeat QUICK TEST.

  6. Check SPOUT Circuit

    Turn ignition off. Set DVOM on DC scale. Disconnect PCM. Disconnect ICM tee of diagnostic harness from ICM. Turn ignition on. Measure voltage between test pins J7 (B-) and J45 (SPOUT). If DC voltage is 0.5 volt or less, go to next step. If voltage is more than 0.5 volt, repair SPOUT circuit short to power. Clear PCM memory and repeat QUICK TEST  .
    NOTE: When PCM is disconnected, continuous memory will be erased and a Code P1000 will be set.

  7. Check SPOUT Circuit

    Turn ignition off. Disconnect diagnostic harness positive lead from battery. Measure resistance between test pins J7 (B-) and J45 (SPOUT). If resistance is more than 10,000 ohms, go to next step. If resistance is 10,000 ohms or less, repair SPOUT circuit short to ground. Clear PCM memory and repeat QUICK TEST.

  8. Check SPOUT Circuit

    Leave ignition off. Install a second breakout box. Measure resistance between test pins J45 (SPOUT) at the first breakout box and test pin 50 at the second breakout box. If resistance is more than 5 ohms, replace PCM. Clear PCM memory and repeat QUICK TEST. If resistance is 5 ohms or less, repair open in SPOUT circuit. Clear PCM memory and repeat QUICK TEST.

  9. Inspect Crankshaft Position (CKP) Sensor & Timing Wheel

    Leave ignition off. Visually inspect CKP sensor and trigger wheel for damage, loose connections or incorrect installation. Repair or replace as necessary. Clear PCM memory and repeat QUICK TEST. If CKP sensor and trigger wheel are okay, replace ICM. Clear PCM memory and repeat QUICK TEST.
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