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Home >> Infiniti >> 2012 >> M37 Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - DTCS P1225 Through P2A03 >> DTC P1572: ICC Brake Switch >> Diagnosis Procedure
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Diagnosis Procedure

  1. CHECK OVERALL FUNCTION-I 

    With CONSULT 

    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 Brake pedal Slightly depressed OFF
      Brake pedal Fully released ON

    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
      M107 126 (ICC brake switch signal) 128 Brake pedal Slightly depressed Approx. 0
      Brake pedal Fully released Battery voltage

      Is the inspection result normal? 

      YES: GO TO 2.

      NO: GO TO  3.

  2. CHECK OVERALL FUNCTION-II 

    With CONSULT 

    Select "BRAKE SW2" and check indication under the following conditions.

    Monitor item Condition Indication
    BRAKE SW2 Brake pedal Slightly depressed ON
    Fully released OFF

    Without CONSULT 

    Check the voltage between ECM harness connector terminals as per the following.

    ECM Condition Voltage (V)
    Connector + -
    Terminal Terminal
    M107 122 (Stop lamp switch signal) 128 Brake pedal Slightly depressed Battery voltage
    Fully released Approx. 0

    Is the inspection result normal? 

    YES: GO TO  14.

    NO: GO TO  8.

  3. CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT 
    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
      E114 1 Ground Battery voltage

      Is the inspection result normal? 

      YES: GO TO  5.

      NO: GO TO 4.

  4. 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.

  5. 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
      E114 2 M107 126 Existed
    4. Also check harness for short to ground and short to power.

      Is the inspection result normal? 

      YES: GO TO  7.

      NO: GO TO 6.

  6. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E106, M6
    • Harness for open or short between ICC brake switch and ECM

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

  7. CHECK ICC BRAKE SWITCH 

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

    Is the inspection result normal? 

    YES: GO TO  14.

    NO: Replace ICC brake switch. Refer to "EXPLODED VIEW ".

  8. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 
    1. Turn ignition switch OFF.
    2. Disconnect stop lamp switch harness connector.
    3. Disconnect ICC brake hold relay harness connector.
    4. Check the voltage between stop lamp switch harness connector and ground.
      Stop lamp switch Ground Voltage
      Connector Terminal
      E110 1 Ground Battery voltage
    5. Check the voltage between ICC brake hold relay harness connector and ground.
      ICC brake hold relay Ground Voltage
      Connector Terminal
      E92 5 Ground Battery voltage

      Is the inspection result normal? 

      YES: GO TO  10.

      NO: GO TO 9.

  9. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector E103
    • 10 A fuse (No. 7)
    • Harness for open or short between battery and stop lamp switch
    • Harness for open or short between battery and ICC brake hold relay

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

  10. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT 
    1. Disconnect ECM harness connector.
    2. Check the continuity between stop lamp switch harness connector and ECM harness connector.
      Stop lamp switch ECM Continuity
      Connector Terminal Connector Terminal
      E110 2 M107 122 Existed
    3. Check the continuity between ICC brake hold relay harness connector and ECM harness connector.
      ICC brake hold relay ECM Continuity
      Connector Terminal Connector Terminal
      E92 3 M107 122 Existed
    4. Also check harness for short to ground and short to power.

      Is the inspection result normal? 

      YES: GO TO  12.

      NO: GO TO 11.

  11. DETECT MALFUNCTIONING PART 

    Check the following.

    • Fuse block (J/B) connector E103, M2
    • Harness for open or short between ECM and stop lamp switch
    • Harness for open or short between ECM and ICC brake hold relay

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

  12. CHECK STOP LAMP SWITCH 

    Refer to "COMPONENT INSPECTION (STOP LAMP SWITCH) ".

    Is the inspection result normal? 

    YES: GO TO 13.

    NO: Replace stop lamp switch. Refer to "EXPLODED VIEW ".

  13. CHECK ICC BRAKE HOLD RELAY 

    Refer to "COMPONENT INSPECTION (ICC BRAKE HOLD RELAY) ".

    Is the inspection result normal? 

    YES: GO TO 14.

    NO: Replace ICC brake hold relay.

  14. CHECK INTERMITTENT INCIDENT 

    Refer to "INTERMITTENT INCIDENT ".

    : INSPECTION END

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