LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2007 >> LS 460 >> Repair and Diagnosis >> External Pages >> Different car >> Section 236 (Engine Control System) >> Ignition Signal >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedure

WARNING: This page is about a different car, the 2005 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK ENGINE START 

    Turn ignition switch OFF, and restart engine.

    Is engine running? 

    Yes or No

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

    With CONSULT-II 

    1. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-II.
      Fig 1: CONSULT-II Active Test
      G02474644Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Make sure that each circuit produces a momentary engine speed drop.

    OK or NG

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

    Without CONSULT-II 

    1. Let engine idle.
    2. Read the voltage signal between ECM terminals 60, 61, 62, 79, 80, 81 and ground with an oscilloscope.
      Fig 2: Checking Voltage Between ECM Terminals 60, 61, 62, 79, 80, 81 & Ground
      G02474646Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Verify that the oscilloscope screen shows the signal wave as shown below.
      NOTE: The pulse cycle changes depending on RPM at idle.
      Fig 3: Pulse Cycle Graph
      G02474645Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    • OK: INSPECTION END 
    • NG: GO TO  10.
  4. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I 
    1. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
      Fig 4: Checking Voltage Between ECM Terminals 119, 120 & Ground
      G02474647Courtesy of NISSAN MOTOR CO., U.S.A.
    2. Check voltage between ECM terminals 119, 120 and ground with CONSULT-II or tester.
      • Voltage: Battery voltage 

    OK or NG

  5. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II 
    1. Turn ignition switch OFF.
    2. Disconnect condenser harness connector.
      Fig 5: Disconnecting Condenser Harness Connector
      G02474648Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn ignition switch ON.
    4. Check voltage between condenser terminal + and ground with CONSULT-II or tester.
      Fig 6: Checking Voltage Between Condenser Terminal (+) & Ground
      G02474649Courtesy of NISSAN MOTOR CO., U.S.A.
      • Voltage: Battery voltage 

    OK or NG

    • OK: GO TO  8.
    • NG: GO TO 6.
  6. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III 
    1. Turn ignition switch OFF.
    2. Disconnect IPDM E/R harness connector E122.
    3. Check harness continuity between IPDM E/R terminal 17 and condenser terminal +.

      Refer to WIRING DIAGRAM .

      • Continuity should exist. 
    4. Also check harness for short to ground and short to power.

    OK or NG

  7. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E5, F14
    • Harness for open or short between IPDM E/R and condenser
    • : Repair open circuit or short to ground or short to power in harness or connectors.
  8. CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check harness continuity between condenser terminal - and ground.

      Refer to WIRING DIAGRAM .

      • Continuity should exist. 
    3. Also check harness for short to power.

    OK or NG

    • OK: GO TO 9.
    • NG: Repair open circuit or short to power in harness or connectors.
  9. CHECK CONDENSER 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 10.
    • NG: Replace condenser.
  10. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-V 
    1. Turn ignition switch OFF.
    2. Reconnect all harness connectors disconnected.
    3. Disconnect ignition coil harness connector.
      Fig 7: Disconnecting Ignition Coil Harness Connector
      G02474650Courtesy of NISSAN MOTOR CO., U.S.A.
    4. Turn ignition switch ON.
    5. Check voltage between ignition coil terminal 3 and ground with CONSULT-II or tester.
      Fig 8: Checking Voltage Between Ignition Coil Terminal 3 & Ground
      G02474651Courtesy of NISSAN MOTOR CO., U.S.A.
      • Voltage: Battery voltage 

    OK or NG

    • OK: GO TO  12.
    • NG: GO TO 11.
  11. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors F43, F201
    • Harness for open or short between ignition coil and harness connector F14
    • : Repair or replace harness or connectors.
  12. CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check harness continuity between ignition coil terminal 2 and ground.

      Refer to WIRING DIAGRAM .

      • Continuity should exist. 
    3. Also check harness for short to power.

    OK or NG

    • OK: GO TO  14.
    • NG: GO TO 13.
  13. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors F201, F43
    • Harness for open or short between ignition coil and ground
    • : 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 60, 61, 62, 79, 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

    • OK: GO TO  16.
    • NG: GO TO 15.
  15. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors F43, F201
    • Harness for open or short between ignition coil and ECM
    • : Repair open circuit or short to ground or short to power in harness or connectors.
  16. CHECK IGNITION COIL WITH POWER TRANSISTOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    • OK: GO TO 17.
    • NG: Replace ignition coil with power transistor.
  17. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    • : INSPECTION END 
scientia non olet · About LEMON Manuals