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Home >> Infiniti >> 2024 >> Q50 Luxe, RWD >> Repair and Diagnosis >> Steering >> Steering Control Systems >> Steering Control System >> Component Parts /Circuit Diagnosis >> Power Supply And Ground Circuit (Steering Angle Main Control Module) >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK STEERING FORCE CONTROL MODULE GROUND CIRCUIT 
    1. Turn the ignition switch OFF.
    2. Disconnect steering force control module harness connector.
    3. Check the continuity between control module harness connector and ground.
      Steering force control module - Continuity
      Connector Terminal
      M72 33 Ground Existed

    Is the inspection result normal?

    YES>>

    GO TO 2.

    NO>>

    Repair open circuit in harness or connectors.

  2. CHECK STEERING ANGLE MAIN CONTROL MODULE GROUND CIRCUIT 
    1. Disconnect steering angle main control module harness connector.
    2. Check the continuity between control module harness connector and ground.
      Steering angle main control module - Continuity
      Connector Terminal
      E27 33 Ground Existed
      E28 39

    Is the inspection result normal?

    YES>>

    GO TO 3.

    NO>>

    Repair open circuit in harness or connectors.

  3. CHECK STEERING ANGLE SUB CONTROL MODULE GROUND CIRCUIT 
    1. Disconnect steering angle sub control module harness connector.
    2. Check the continuity between control module harness connector and ground.
      Steering angle sub control module - Continuity
      Connector Terminal
      E30 33 Ground Existed
      E31 39

    Is the inspection result normal?

    YES>>

    GO TO 4.

    NO>>

    Repair open circuit in harness or connectors.

  4. CHECK STEERING FORCE CONTROL MODULE POWER SUPPLY CIRCUIT (1) 
    1. Disconnect steering force control module harness connector.
    2. Check the voltage between steering force control module harness connector and ground.
      + - Voltage
      Steering force control module
      Connector Terminal
      M72 34 Ground 10.5 - 16.0 V

    Is the inspection result normal?

    YES>>

    GO TO 6.

    NO>>

    GO TO 5.

  5. CHECK STEERING FORCE CONTROL MODULE POWER SUPPLY CIRCUIT (2) 
    1. Check the 60A fusible link (#G). (With pre-crash seat belt system)
    2. Check the 60A fusible link (#I). (Without pre-crash seat belt system)
    3. Check the harness for open or short between steering force control module harness connector No. 34 terminal and the 60A fusible link (#G). (With pre-crash seat belt system)
    4. Check the harness for open or short between steering angle sub control module harness connector No. 34 terminal and the 60A fusible link (#I). (Without pre-crash seat belt system)

    Is the inspection result normal?

    YES>>

    Perform the trouble diagnosis for 12V battery power supply circuit.

    NO>>

    Repair / replace harness, connector, or fusible link.

  6. CHECK STEERING ANGLE MAIN CONTROL MODULE POWER SUPPLY CIRCUIT (1) 
    1. Turn the ignition switch OFF.
    2. Disconnect steering angle main control module harness connector.
    3. Check the voltage between steering angle main control module harness connector and ground.
      + - Voltage
      Steering angle main control module
      Connector Terminal
      E27 34 Ground 10.5 - 16.0 V

    Is the inspection result normal?

    YES>>

    GO TO 8.

    NO>>

    GO TO 7.

  7. CHECK STEERING ANGLE MAIN CONTROL MODULE POWER SUPPLY CIRCUIT (2) 
    1. Check the 100A fusible link (#J).
    2. Check the harness for open or short between steering angle main control module harness connector No. 34 terminal and the 100A fusible link (#J).

    Is the inspection result normal?

    YES>>

    Perform the trouble diagnosis for 12V battery power supply circuit.

    NO>>

    Repair / replace harness, connector, or fusible link.

  8. CHECK STEERING ANGLE SUB CONTROL MODULE POWER SUPPLY CIRCUIT (1) 
    1. Turn the ignition switch OFF.
    2. Disconnect steering angle sub control module harness connector.
    3. Check the voltage between steering angle sub control module harness connector and ground.
      + - Voltage
      Steering angle sub control module
      Connector Terminal
      E30 34 Ground 10.5 - 16.0 V

    Is the inspection result normal?

    YES>>

    GO TO 10.

    NO>>

    GO TO 9.

  9. CHECK STEERING ANGLE SUB CONTROL MODULE POWER SUPPLY CIRCUIT (2) 
    1. Check the 100A fusible link (#H). (With pre-crash seat belt system)
    2. Check the 100A fusible link (#K). (Without pre-crash seat belt system)
    3. Check the harness for open or short between steering angle sub control module harness connector No. 34 terminal and the 100A fusible link (#H). (With pre-crash seat belt system)
    4. Check the harness for open or short between steering angle sub control module harness connector No. 34 terminal and the 100A fusible link (#K). (Without pre-crash seat belt system)

    Is the inspection result normal?

    YES>>

    Perform the trouble diagnosis for 12V battery power supply circuit.

    NO>>

    Repair / replace harness, connector, or fusible link.

  10. CHECK IGNITION POWER SUPPLY FOR STEERING ANGLE MAIN CONTROL MODULE 
    1. Turn the ignition switch OFF.
    2. Disconnect steering angle main control module harness connector.
    3. Check the voltage between steering angle main control module harness connector and ground.
      + - Voltage
      Steering angle main control module
      Connector Terminal
      E26 25 Ground Approx. 0 V
    4. Turn the ignition switch ON.
    5. Check the voltage between steering angle main control module harness connector and ground.
      + - Voltage
      Steering angle main control module
      Connector Terminal
      E26 25 Ground 10.5 - 16.0 V

    Is the inspection result normal?

    YES>>

    INSPECTION END

    NO>>

    GO TO 11.

  11. CHECK IGNITION POWER SUPPLY CIRCUIT (1) 
    1. Turn the ignition switch OFF.
    2. Disconnect steering angle sub control module harness connector.
    3. Check the continuity between steering angle main control module harness connector and steering angle sub control module harness connector.
      Steering angle main control module Steering angle sub control module Continuity
      Connector Terminal Connector Terminal
      E26 25 E29 27 Existed

    Is the inspection result normal?

    YES>>

    GO TO 12.

    NO>>

    Repair / replace harness or connector.

  12. CHECK INTERNAL CIRCUIT IN STEERING ANGLE SUB CONTROL MODULE 

    Check the continuity between steering angle sub control module connector terminals.

    Steering angle sub control module Continuity
    Terminal
    25 27 Existed

    Is the inspection result normal?

    YES>>

    GO TO 13.

    NO>>

    Replace steering angle sub control module. Refer to STEERING ANGLE SUB CONTROL MODULE : Removal and Installation .

  13. CHECK IGNITION POWER SUPPLY FOR STEERING ANGLE SUB CONTROL MODULE 
    1. Check the voltage between steering angle sub control module harness connector and ground.
      + - Voltage
      Steering angle sub control module
      Connector Terminal
      E29 25 Ground Approx. 0 V
    2. Turn the ignition switch ON.
    3. Check the voltage between steering angle sub control module harness connector and ground.
      + - Voltage
      Steering angle sub control module
      Connector Terminal
      E29 25 Ground 10.5 - 16.0 V

    Is the inspection result normal?

    YES>>

    • Check enlarged contact spring of terminal. Refer to Inspection .
    • Perform intermittent incident while turning steering wheel. Refer to Inspection .

    NO>>

    GO TO 14.

  14. CHECK IGNITION POWER SUPPLY CIRCUIT (2) 
    1. Turn the ignition switch OFF.
    2. Disconnect steering force control module harness connector.
    3. Check the continuity between steering angle sub control module harness connector and steering force control module harness connector.
      Steering angle sub control module Steering force control module Continuity
      Connector Terminal Connector Terminal
      E29 25 M71 27 Existed

    Is the inspection result normal?

    YES>>

    GO TO 15.

    NO>>

    Repair / replace harness or connector.

  15. CHECK INTERNAL CIRCUIT IN STEERING FORCE CONTROL MODULE 

    Check the continuity between steering force control module connector terminals.

    Steering force control module Continuity
    Terminal
    25 27 Existed

    Is the inspection result normal?

    YES>>

    GO TO 16.

    NO>>

    Replace steering force control module. Refer to STEERING FORCE CONTROL MODULE : Removal and Installation .

  16. CHECK IGNITION POWER SUPPLY FOR STEERING FORCE CONTROL MODULE 
    1. Check the voltage between steering force control module harness connector and ground.
      + - Voltage
      Steering force control module
      Connector Terminal
      M71 25 Ground Approx. 0 V
    2. Turn the ignition switch ON.
    3. Check the voltage between force control module harness connector and ground.
      + - Voltage
      Steering force control module
      Connector Terminal
      M71 25 Ground 10.5 - 16.0 V

    Is the inspection result normal?

    YES>>

    • Check enlarged contact spring of terminal. Refer to Inspection .
    • Perform intermittent incident while turning steering wheel. Refer to Inspection .

    NO>>

    GO TO 17.

  17. CHECK IGNITION POWER SUPPLY CIRCUIT (3) 
    1. Turn the ignition switch OFF.
    2. Check the 10A fuse (#12).
    3. Disconnect fuse block (J/B) harness connector.
    4. Check the continuity between steering force control module connector and fuse block (J/B).
      Steering force control module Fuse block (J/B) Continuity
      Connector Terminal Connector Terminal
      M71 25 M133 20C Existed
    5. Check the continuity between steering force control module connector and ground.
      Steering force control module - Continuity
      Connector Terminal
      M71 25 Ground Not existed

    Is the inspection result normal?

    YES>>

    Perform the trouble diagnosis for ignition power supply circuit.

    NO>>

    Repair / replace harness, connector, or fuse.

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