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Home >> Infiniti >> 2024 >> QX80 Premium Select, AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System (2 Of 2) >> Component /Circuit Diagnosis >> ICC Brake Switch >> Diagnosis Procedure

Diagnosis Procedure

  1. CHECK DTC WITH ADAS CONTROL UNIT 

    Refer to Diagnosis Description . and Refer to DTC Index .Are any DTCs detected?

    YES>>

    Perform the Diagnosis Procedure corresponding to the detected DTC.

    NO>>

    GO TO 2.

  2. CHECK OVERALL FUNCTION SYMBOL
    1. Turn ignition switch ON.
    2. Select "BRAKE SW1" in "DATA MONITOR" mode with CONSULT.
    3. Check "BRAKE SW1" indication under the following conditions.
      Monitor item Condition Indication
      BRAKE SW1
      (ICC brake switch)      		 Brake pedal Slightly depressed OFF
      Fully released ON

    SYMBOL 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
      E20 140
      (ICC brake switch signal)      		 152 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.
      ICC brake switch Ground Voltage
      Connector Terminal
      E68 2 Ground 0 V

    Is the inspection result normal?

    YES>>

    GO TO 4.

    NO>>

    GO TO 7.

  4. CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-II 

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

    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 .Is the inspection result normal?

    YES>>

    GO TO 9.

    NO>>

    Replace ICC brake switch. Refer to BRAKE PEDAL : Exploded View .

  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.
      ICC brake switch ECM Continuity
      Connector Terminal Connector Terminal
      E68 2 E20 140 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 Inspection .

    >>

    INSPECTION END

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