Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Infiniti >> 2022 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (Diagnostics) (1 Of 2) >> Component/Circuit Diagnosis >> Ignition Signal >> Diagnosis Procedure

Diagnosis Procedure

  1. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I 
    1. Turn ignition switch OFF, wait at least 10 seconds and then turn it ON.
    2. Check the voltage between ECM harness connector terminals under the following conditions.

      ECM

      Voltage

      Connector

      +

      -

      Terminal

      Terminal

      E20

      145

      152

      Battery voltage

    Is the inspection result normal?

    YES

    GO TO 2.

    NO

    Go to Diagnosis Procedure .

  2. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II 
    1. Turn ignition switch OFF.
    2. Disconnect condenser harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between condenser harness connector and ground.

      Condenser

      Ground

      Voltage

      Connector

      Terminal

      F8

      1

      Ground

      Battery voltage

    Is the inspection result normal?

    YES

    GO TO 5.

    NO

    GO TO 3.

  3. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III 
    1. Turn ignition switch OFF.
    2. Disconnect IPDM E/R harness connector E7.
    3. Check the continuity between IPDM E/R harness connector and condenser harness connector.

      IPDM E/R

      Condenser

      Continuity

      Connector

      Terminal

      Connector

      Terminal

      E15

      61

      F8

      1

      Existed

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

    Is the inspection result normal?

    YES

    Go to Diagnosis Procedure .

    NO

    GO TO 4.

  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness for open or short between IPDM E/R and condenser
    • Loose or poor connection for each connector and harness

    Repair open circuit, short to ground or short to power in harness or connectors.

  5. CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check the continuity between condenser harness connector and ground.

      Condenser

      Ground

      Continuity

      Connector

      Terminal

      F8

      2

      Ground

      Existed

    3. Also check harness for short to power.

    Is the inspection result normal?

    YES

    GO TO 6.

    NO

    Repair open circuit or short to power in harness or connectors.

  6. CHECK CONDENSER 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 7.

    NO

    Replace condenser.

  7. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-IV 
    1. Reconnect all harness connectors disconnected.
    2. Disconnect ignition coil harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between ignition coil harness connector and ground.

      Ignition coil

      Ground

      Voltage

      Cylinder

      Connector

      Terminal

      1

      F75

      3

      Ground

      Battery voltage

      2

      F76

      3

      3

      F77

      3

      4

      F78

      3

      5

      F79

      3

      6

      F80

      3

      7

      F81

      3

      8

      F82

      3

    Is the inspection result normal?

    YES

    GO TO 9.

    NO

    GO TO 8.

  8. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connector F22 and E46
    • Harness for open or short between ignition coil and harness connector F22

    Repair or replace harness or connectors.

  9. CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Check the continuity between ignition coil harness connector and ground.

      Ignition coil

      Ground

      Continuity

      Cylinder

      Connector

      Terminal

      1

      F75

      2

      Ground

      Existed

      2

      F76

      2

      3

      F77

      2

      4

      F78

      2

      5

      F79

      2

      6

      F80

      2

      7

      F81

      2

      8

      F82

      2

    3. Also check harness for short to power.

    Is the inspection result normal?

    YES

    GO TO 10.

    NO

    Repair open circuit or short to power in harness or connectors.

  10. CHECK IGNITION COIL OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. Check the continuity between ignition coil harness connector and ECM harness connector.

      Ignition coil

      ECM

      Continuity

      Cylinder

      Connector

      Terminal

      Connector

      Terminal

      1

      F75

      1

      F92

      95

      Existed

      2

      F76

      1

      91

      3

      F77

      1

      92

      4

      F78

      1

      104

      5

      F79

      1

      102

      6

      F80

      1

      94

      7

      F81

      1

      105

      8

      F82

      1

      101

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

    Is the inspection result normal?

    YES

    GO TO 11.

    NO

    Repair open circuit, short to ground or short to power in harness or connectors.

  11. CHECK IGNITION COIL WITH POWER TRANSISTOR 

    Refer to Component Inspection .

    Is the inspection result normal?

    YES

    GO TO 12.

    NO

    Replace malfunctioning ignition coil with power transistor.

  12. CHECK INTERMITTENT INCIDENT 

    Refer to Inspection .

    INSPECTION END