LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2012 >> EX35 Base, AWD >> Repair and Diagnosis >> Steering >> Power Steering >> Steering Control System >> DTC/Circuit Diagnosis >> Engine Speed Signal Circuit >> Diagnosis Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis Procedure

  1. PERFORM ECM SELF-DIAGNOSIS

    With CONSULT 

    1. Turn the ignition switch ON.

      Perform "ENGINE" self-diagnosis. Refer to "CONSULT FUNCTION ".

      Is any DTC detected? 

      YES: Check the DTC.

      NO: GO TO 2.

  2. CHECK HARNESS BETWEEN ECM AND POWER STEERING CONTROL UNIT
    1. Turn the ignition switch OFF.
    2. Disconnect ECM harness connectors.
    3. Disconnect power steering control unit harness connector.
    4. Check continuity between ECM harness connector and power steering control unit harness connector.
      ECM Power steering control unit Continuity
      Connector Terminal Connector Terminal
      M107 110 M108 10 Existed
    5. Check continuity between power steering control unit harness connector and ground.
      Power steering control unit - Continuity
      Connector Terminal
      M108 10 Ground Not existed

      Is the inspection result normal? 

      YES: GO TO 3.

      NO: Repair or replace damaged parts.

  3. CHECK ENGINE SPEED SIGNAL (1)
    1. Connect ECM harness connectors.
    2. Check signal between ECM harness connector and ground with oscilloscope.
      ECM - Condition Voltage (Approx.)
      Connector Terminal
      M107 110 Ground Engine is running
      • Warm-up condition
      • Idle speed
      G05889754
      Engine is running
      • Warm-up condition
      • Engine speed: Approx. 2, 000 RPM
      G05729713

      Is the inspection result normal? 

      YES: GO TO 4.

      NO: Replace ECM. Refer to "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT: DESCRIPTION ".

  4. CHECK ENGINE SPEED SIGNAL (2)
    1. Turn the ignition switch OFF.
    2. Connect power steering control unit harness connector.
    3. Check signal between power steering control unit harness connector and ground with oscilloscope.
      Power steering control unit - Condition Voltage (Approx.)
      Connector Terminal
      M108 10 Ground Engine is running
      • Warm-up condition
      • Idle speed
      G05729712
      Engine is running
      • Warm-up condition
      • Engine speed: Approx. 2, 000 RPM
      G05729713

      Is the inspection result normal? 

      YES: GO TO 5.

      NO: Replace power steering control unit. Refer to "EXPLODED VIEW ".

  5. CHECK TERMINALS AND HARNESS CONNECTORS
    • Check power steering control unit pin terminals for damage or loose connection with harness connector.
    • Check ECM pin terminals for damage or loose connection with harness connector.

      Is the inspection result normal? 

      YES: INSPECTION END

      NO: Repair or replace damaged parts.

scientia non olet · About LEMON Manuals