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Home >> Nissan-Datsun >> 1989 >> Sentra Base >> Repair and Diagnosis >> Engine Performance >> System >> System/Component Tests >> Fuel Control System >> Feedback System >> Notes
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Feedback System: Notes

  1. Start engine and warm to operating temperature. Ensure idle speed and timing are adjusted to specification. Increase engine speed to about 2000 RPM for 2 minutes under no-load condition. Monitor Green LED on ECU. With engine speed at 2000 RPM, Green LED should flash at least the appropriate number of times during a 10 second period. See GREEN LED FEEDBACK RESPONSE table in this article.
  2. Race engine 2 or 3 times and allow to idle. Enter self-diagnostic mode 2 and monitor and disconnect throttle sensor/switch harness connector. Monitor Red and Green LEDs while idling. Red and Green LEDs should flash simultaneously. If LEDs do not respond as described, adjust airflow meter (if adjustable). See ADJUSTMENTS article.
  3. If airflow meter adjustment does not affect LEDS, and ECU self-diagnostic system flashes only code 55 (pass), either airflow meter, oxygen sensor, or ECU is defective.
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