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Home >> Nissan-Datsun >> 1990 >> 300ZX Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Fuel Control System >> Feedback System
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Feedback System

  1. A single Red LED, located on the ECU, is used. 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; enter self-diagnostic Mode II and monitor Red LED on ECU.
  2. Note the number of flashes by Green LED every 10 seconds. See ECU RED LED FEEDBACK RESPONSE  table. Number of flashes during a 10-second period should at least equal number of flashes listed in table.
  3. If Red LED does not respond as described, check oxygen sensor(s) and/or adjust idle mixture (CO percentage level). See ADJUSTMENTS article. If idle mixture adjustment does not affect LED operation, check fuel pressure regulator, airflow meter, injector(s), engine (coolant) temperature sensor or ECU.
ECU RED LED FEEDBACK RESPONSE

Application (1) Flashes (@ 2000 RPM)
300ZX 5
(1) Number of flashes in 10-second period.