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Home >> Infiniti >> 2011 >> QX56 RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Component Testing >> ICC Brake Switch >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK DTC WITH ADAS CONTROL UNIT

    Refer to "CONSULT-III FUNCTION (ICC/ADAS) " and "DTC INDEX ".

    Are any DTCs detected? 

    YES: Perform the Diagnosis Procedure corresponding to the detected DTC.

    NO: GO TO 2.

  2. CHECK OVERALL FUNCTION

    WITH CONSULT-III

    1. Turn ignition switch ON.
    2. Select "BRAKE SW1" in "DATA MONITOR" mode with CONSULT-III.
    3. Check "BRAKE SW1" indication under the following conditions.
      MONITOR ITEM CONDITION

      Monitor item Condition Indication
      BRAKE SW1 (ICC brake switch) Brake pedal Slightly depressed OFF
      Fully released ON

    WITHOUT CONSULT-III

    1. Turn ignition switch ON.
    2. Check the voltage between ECM harness connector terminals under the following conditions.
      VOLTAGE SPECIFICATION

      ECM Condition Voltage (V)
      Connector + -
      Terminal Terminal
      E80 147 (ICC brake switch signal) 175 Brake pedal Slightly depressed Approx. 0
      Fully released Battery voltage

      Is the inspection result normal? 

      YES: INSPECTION END

      NO: GO TO 3.

  3. CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-I
    1. Turn ignition switch OFF.
    2. Disconnect ICC brake switch harness connector.
    3. Turn ignition switch ON.
    4. Check the voltage between ICC brake switch harness connector and ground.
      VOLTAGE SPECIFICATION

      ICC brake switch Ground Voltage
      Connector Terminal
      E68 2 Ground Battery voltage

      Is the inspection result normal? 

      YES: GO TO  7.

      NO: GO TO 4.

  4. CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-II

    Check the voltage between ICC brake switch harness connector and ground.

    VOLTAGE SPECIFICATION

    ICC brake switch Ground Voltage
    Connector Terminal
    E68 1 Ground Battery voltage

    Is the inspection result normal? 

    YES: GO TO  6.

    NO: GO TO 5.

  5. DETECT MALFUNCTIONING PART

    Check the following.

    • Fuse block (J/B) connector E103
    • 10 A fuse (No. 3)
    • Harness for open or short between ICC brake switch and fuse

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

  6. CHECK ICC BRAKE SWITCH

    Refer to "COMPONENT INSPECTION (ICC BRAKE SWITCH) ".

    Is the inspection result normal? 

    YES: GO TO  9.

    NO: Replace ICC brake switch. Refer to "REMOVAL AND INSTALLATION ".

  7. CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check the continuity between ICC brake switch harness connector and ECM harness connector.
      CONTINUITY SPECIFICATION

      ICC brake switch ECM Continuity
      Connector Terminal Connector Terminal
      E68 2 E80 147 Existed
    4. Also check harness for short to ground and short to power.

      Is the inspection result normal? 

      YES: GO TO  9.

      NO: GO TO 8.

  8. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness for open or short between ICC brake switch and ECM
    • Loose or poor connection for each connector and harness

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

  9. CHECK INTERMITTENT INCIDENT

    Refer to "INTERMITTENT INCIDENT ".

    INSPECTION END

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