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Home >> Nissan-Datsun >> 2004 >> Sentra SE-R >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Qr25DE >> Ignition Signal >> Diagnostic Procedure
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Diagnostic Procedure

  1. CHECK ENGINE START 

    Turn ignition switch OFF, and restart engine.

    Is engine running? 

    Yes or No 

    1. Yes (With CONSULT-II): GO TO 2.
    2. Yes (Without CONSULT-II): GO TO  3.
    3. No: GO TO  4.
  2. CHECK OVERALL FUNCTION 

    WITH CONSULT-II 

    1. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-II.
    2. Make sure that all circuits do not produce a momentary engine speed drop.
      3. Fig 1: Displaying Active Test Mode With Consult-II
      G00779527Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: INSPECTION END 
    2. NG: GO TO  10.
  3. CHECK OVERALL FUNCTION 

    Without CONSULT-II 

    1. Let engine idle.
    2. Read the voltage signal between ECM terminals 61, 62, 80, 81 and ground with an oscilloscope.
    3. Verify that the oscilloscope screen shows the signal wave as shown below.
    Fig 2: Identifying Signal Wave Form
    G00779528Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 3: Identifying Voltage Signal Between ECM Terminals 61, 62, 80, 81 & Ground
    G00779529Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: INSPECTION END 
    2. NG: GO TO  10.
  4. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I 
    1. Turn ignition switch ON.
    2. Check voltage between ECM terminals 119, 120 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

      3. Fig 4: Checking Voltage Between ECM Terminals 119, 120 & Ground
      G00779530Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 5.
    2. NG: GO TO "POWER SUPPLY CIRCUIT FOR ECM ".
  5. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II 
    1. Turn ignition switch OFF.
    2. Disconnect condenser harness connector.
    3. Turn ignition switch ON.
    4. Check voltage between condenser terminal + and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

      5. Fig 5: Checking Voltage Between Condenser Terminal + & Ground
      G00779531Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO  10.
    2. NG: GO TO 6.
  6. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III 
    1. Turn ignition switch OFF.
    2. Disconnect ECM relay.
    3. Check harness continuity between ECM relay terminal 7 and condenser terminal +.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    4. Also check harness for short to ground and short to power.
      5. Fig 6: Disconnecting ECM Relay
      G00779532Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 7.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  7. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-IV 

    Check voltage between ECM relay terminal 6 and ground with CONSULT-II or tester.

    Voltage: Battery voltage 

    Fig 7: Checking Voltage Between ECM Relay Terminal 6 & Ground
    G00779533Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO  9.
    2. NG: GO TO 8.
  8. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E10, F48
    • Fuse and fusible link box connector E22
    • 15A fuse
    • Harness for open or short between ECM relay and battery
      1. Repair or replace harness or connectors.
  9. CHECK ECM RELAY 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO  16.
    2. NG: Replace ECM relay.
  10. CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect condenser harness connector.
    3. Check harness continuity between condenser terminal - and ground. Refer to WIRING DIAGRAM .

      Continuity should exist. 

    4. Also check harness for short to power.

    OK or NG 

    1. OK: GO TO 11.
    2. NG: Repair open circuit or short to power in harness or connector.
  11. CHECK CONDENSER 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO 12.
    2. NG: Replace condenser.
  12. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-V 
    1. Turn ignition switch OFF.
    2. Reconnect all harness connectors disconnected.
    3. Disconnect ignition coil harness connector.
    4. Turn ignition switch ON.
      Fig 8: Disconnecting Ignition Coil Harness Connectors
      G00779534Courtesy of NISSAN MOTOR CO., U.S.A.
    5. Check voltage between ignition coil terminal 3 and ground with CONSULT-II or tester.

      Voltage: Battery voltage 

      6. Fig 9: Checking Voltage Between Ignition Coil Terminal 3 & Ground
      G00779535Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 13.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  13. CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check harness continuity between ignition coil terminal 2 and engine ground. Refer to WIRING DIAGRAM .

      Continuity should exist. 

    3. Also check harness for short to power.

    OK or NG 

    1. OK: GO TO 14.
    2. NG: Repair open circuit or short to power in harness or connectors.
  14. CHECK IGNITION COIL OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminals 61, 62, 80, 81 and ignition coil terminal 1.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    3. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO 15.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  15. CHECK IGNITION COIL WITH POWER TRANSISTOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    1. OK: GO TO 16.
    2. NG: Replace ignition coil with power transistor.
  16. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. INSPECTION END 
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