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Home >> Honda >> 1989 >> Prelude S, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Tests W/Codes - Fuel Injected >> Testing - Trouble Code Tests >> Code 4: TDC/Crank Sensor

Code 4: TDC/Crank Sensor

  1. Turn ignition off. Remove clock fuse in the under-hood relay box for 10 seconds to reset ECU. Start engine and observe "CHECK ENGINE" light. If light is off, problem is intermittent. Test drive and check again.
  2. If light is on, turn ignition off. Disconnect TDC/CRANK sensor connector nearest the sensor. Measure resistance across terminals "C" and "D" at sensor. See Fig 1 . If reading is not 700-1000 ohms, replace distributor assembly. If reading is within specification, proceed to next step.
  3. Check continuity between ground and sensor terminals "C" and "D". If continuity exists, sensor is shorted to ground. Replace distributor assembly. If no continuity exists, proceed to next step.
  4. Reconnect sensor connector. Connect ECU test harness to main harness side only. See Figure . Check resistance between connector terminals B10 and B12. Resistance should be 700-1000 ohms.
  5. If resistance is not within specification, repair open in Blue/Yellow and/or Blue/Green wire. If resistance is within specification, substitute a known good ECU and recheck. If condition is rectified, replace original ECU.
    Fig 1: TDC/CRANK Sensor Connector
    G117903Courtesy of AMERICAN HONDA MOTOR CO., INC.