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Home >> Infiniti >> 2013 >> M56 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P1087 To P2542 >> DTC P1564: ASCD Steering Switch >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK ASCD STEERING SWITCH CIRCUIT 

    WITH CONSULT

    1. Turn ignition switch ON.
    2. Select "MAIN SW", "CANCEL SW", "RESUME/ACC SW" and "SET SW" in "DATA MONITOR" mode with CONSULT.
    3. Check each item indication under the following conditions.
      Monitor item Condition Indication
      MAIN SW MAIN switch Pressed ON
      Released OFF
      CANCEL SW CANCEL switch Pressed ON
      Released OFF
      RESUME/ACC SW RESUME/ACCELERATE switch Pressed ON
      Released OFF
      SET SW SET/COAST switch Pressed ON
      Released OFF

    WITHOUT CONSULT

    1. Turn ignition switch ON.
    2. Check the voltage between ECM harness connector terminals under the following conditions.
      ECM Condition Voltage (V)
      Connector + -
      Terminal Terminal
      M160 128 (ASCD steering switch signal) 130 MAIN switch: Pressed Approx. 0
      CANCEL switch: Pressed Approx. 1
      COAST/SET switch: Pressed Approx. 2
      ACCELERATE/RESUME switch: Pressed Approx. 3
      All ASCD steering switches: Released Approx. 4

      Is the inspection result normal? 

      YES: GO TO  7.

      NO: GO TO 2.

  2. CHECK ASCD STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT 
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Disconnect combination switch harness connector.
    4. Check the continuity between combination switch and ECM harness connector.
      Combination switch ECM Continuity
      Connector Terminal Connector Terminal
      M303 16 M160 130 Existed
    5. Also check harness for short to ground and short to power.

      Is the inspection result normal? 

      YES: GO TO  4.

      NO: GO TO 3.

  3. DETECT MALFUNCTIONING PART 

    Check the following.

    • Combination switch (spiral cable)
    • Harness for open and short between ECM and combination switch

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

  4. CHECK ASCD STEERING SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Check the continuity between combination switch and ECM harness connector.
      Combination switch ECM Continuity
      Connector Terminal Connector Terminal
      M303 13 M160 128 Existed
    2. Also check harness for short to ground and short to power.

      Is the inspection result normal? 

      YES: GO TO  6.

      NO: GO TO 5.

  5. DETECT MALFUNCTIONING PART 

    Check the following.

    • Combination switch (spiral cable)
    • Harness for open and short between ECM and combination switch

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

  6. CHECK ASCD STEERING SWITCH 

    Refer to "COMPONENT INSPECTION (ASCD STEERING SWITCH) ".

    Is the inspection result normal? 

    YES: GO TO 7.

    NO: Replace ASCD steering switch. Refer to "ENGINE CONTROL SYSTEM: COMPONENT PARTS LOCATION ".

  7. CHECK INTERMITTENT INCIDENT 

    Refer to "INTERMITTENT INCIDENT ".

    : INSPECTION END

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