LEMON Manuals: Even more car manuals for everyone
Home >> Infiniti >> 2024 >> QX55 Essential >> Repair and Diagnosis >> Brakes >> Traction Control >> Brake Control System (VDC/TCS/Abs) (DTC/Circuit Diagnosis) >> DTC/Circuit Diagnosis >> Power Supply And Ground Circuit >> Diagnosis Procedure

Diagnosis Procedure

  1. CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) IGNITION POWER SUPPLY 
      1. Ignition switch OFF.
      2. Disconnect ABS actuator and electric unit (control unit) harness connector.
      3. Check the voltage between ABS actuator and electric unit (control unit) harness connector and ground.
        ABS actuator and electric unit (control unit) - Voltage(Approx.)
        Connector Terminal
        E125 28 Ground 0 V
      4. Ignition switch ON
        NOTE: SYMBOL Start the engine.
      5. Check the voltage between ABS actuator and electric unit (control unit) harness connector and ground.
        ABS actuator and electric unit (control unit) - Voltage(Approx.)
        Connector Terminal
        E125 28 Ground Battery voltage

    Is the inspection result normal?

    YES>>

    GO TO 3.

    NO>>

    GO TO 2.

  2. CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) IGNITION POWER SUPPLY CIRCUIT 
      1. Ignition switch OFF.
      2. Check the 5A fuse (48).
      3. Disconnect fuse block (J/B) harness connector.
      4. Check the continuity between ABS actuator and electric unit (control unit) harness connector and fuse block (J/B).
        ABS actuator and electric unit (control unit) Fuse block (J/B) Continuity
        Connector Terminal Connector Terminal
        E125 28 E28 2P Yes
      5. Check the continuity between ABS actuator and electric unit (control unit) harness connector and ground.
        ABS actuator and electric unit (control unit) - Continuity
        Connector Terminal
        E125 28 Ground No

    Is the inspection result normal?

    YES>>

    Perform trouble diagnosis for ignition power supply.

    NO>>

    Repair / replace harness, connector, or fuse.

  3. CHECK MOTOR AND MOTOR RELAY POWER SUPPLY 
      1. Ignition switch OFF.
      2. Check the voltage between ABS actuator and electric unit (control unit) harness connector and ground.
        ABS actuator and electric unit (control unit) - Voltage(Approx.)
        Connector Terminal
        E125 1 Ground Battery voltage
      3. Ignition switch ON.
        NOTE: SYMBOL Start the engine.
      4. Check the voltage between ABS actuator and electric unit (control unit) harness connector and ground.
        ABS actuator and electric unit (control unit) - Voltage(Approx.)
        Connector Terminal
        E125 1 Ground Battery voltage

    Is the inspection result normal?

    YES>>

    GO TO 5.

    NO>>

    GO TO 4.

  4. CHECK MOTOR AND MOTOR RELAY POWER SUPPLY CIRCUIT 
      1. Ignition switch OFF.
      2. Check the 40A fusible link (V).
      3. Check the continuity and short circuit between ABS actuator and electric unit (control unit) harness connector terminal 1 and 40A fusible link (V).

    Is the inspection result normal?

    YES>>

    Perform trouble diagnosis for battery power supply.

    NO>>

    Repair / replace harness, connector, or fusible link.

  5. CHECK ACTUATOR RELAY, ABS IN VALVE, ABS OUT VALVE POWER SUPPLY 
      1. Ignition switch OFF.
      2. Check the voltage between ABS actuator and electric unit (control unit) harness connector and ground.
        ABS actuator and electric unit (control unit) - Voltage(Approx.)
        Connector Terminal
        E125 25 Ground Battery voltage
      3. Ignition switch ON
        NOTE: SYMBOL Start the engine.
      4. Check the voltage between ABS actuator and electric unit (control unit) harness connector and ground.
        ABS actuator and electric unit (control unit) - Voltage(Approx.)
        Connector Terminal
        E125 25 Ground Battery voltage

    Is the inspection result normal?

    YES>>

    GO TO 7.

    NO>>

    GO TO 6.

  6. CHECK ACTUATOR RELAY, ABS IN VALVE, ABS OUT VALVE POWER SUPPLY CIRCUIT 
      1. Ignition switch OFF.
      2. Check the 30A fusible link (K).
      3. Check the continuity and short circuit between ABS actuator and electric unit (control unit) harness connector terminal 25 and 30A fusible link (K).

    Is the inspection result normal?

    YES>>

    Perform trouble diagnosis for battery power supply.

    NO>>

    Repair / replace harness, connector, or fusible link.

  7. CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) GROUND CIRCUIT 
    1. Check the continuity between ABS actuator and electric unit (control unit) harness connector and the ground.
      ABS actuator and electric unit (control unit) - Continuity
      Connector Terminal
      E125 13 Ground Yes
      38

    Is the inspection result normal?

    YES>>

    GO TO 8.

    NO>>

    Repair / replace harness, connector, or terminal.

  8. CHECK TERMINAL 
      1. Check the ABS actuator and electric unit (control unit) pin terminals for damage or loose connection with harness connector.
      2. Check the fuse block J/B pin terminals for damage or loose connection with harness connector.

    Is the inspection result normal?

    YES>>

    Replace the ABS actuator and electric unit (control unit). Refer to Removal and Installation .

    NO>>

    Repair / replace harness, connector, or terminal.

scientia non olet · About LEMON Manuals