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Home >> Infiniti >> 2004 >> FX35 RWD >> Repair and Diagnosis >> Engine Performance >> Engine Control System >> DTC P1572 ICC Brake Switch >> Diagnostic Procedure
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Diagnostic Procedure

  1. Check Overall Function-I 

    With CONSULT-II 

    1. Turn ignition switch ON.
    2. Select BRAKE SW1 in DATA MONITOR mode with CONSULT-II.
    3. Check BRAKE SW1 indication under the following conditions.
      Fig 1: Testing BRAKE SW1 Circuit With CONSULT-II
      G00727716Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 2: Identifying Brake Switch 1 Specifications (CONSULT-II)
      G00727715Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

    1. Turn ignition switch ON.
    2. Check voltage between ECM terminal 108 and ground under the following conditions.
      Fig 3: Testing ECM Signal To Brake Switch 1 Circuit (W/DVOM)
      G00727718Courtesy of NISSAN MOTOR CO., U.S.A.
      Fig 4: Identifying Brake Switch 1 Circuit Specifications (W/DVOM)
      G00727717Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    1. OK: Go to 2.
    2. NG: Go to 3.

  2. Check Overall Function-II 

    With CONSULT-II 

    Check BRAKE SW2 indication in DATA MONITOR mode.

    Fig 5: Testing BRAKE SW2 Circuit With CONSULT-II
    G00727720Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 6: Identifying Brake Switch 2 Specifications (CONSULT-II)
    G00727719Courtesy of NISSAN MOTOR CO., U.S.A.

    Without CONSULT-II 

    Check voltage between ECM terminal 101 and ground under the following conditions.

    Fig 7: Testing Stop Lamp Switch Circuit (W/DVOM)
    G00727722Courtesy of NISSAN MOTOR CO., U.S.A.
    Fig 8: Identifying ECM Terminal 101 Specifications (W/DVOM)
    G00727721Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG

    1. OK: Go to 15.
    2. NG: Go to 11.

  3. Check ICC Brake Switch Circuit 
    1. Turn ignition switch OFF.
    2. Disconnect ICC brake hold relay.
      Fig 9: Locating ICC Brake Hold Relay
      G00727723Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn ignition switch ON.
    4. Check voltage between ICC brake hold relay terminal 3 and ground with CONSULT-II or tester.
      Fig 10: Testing Circuit Through ICC Brake Hold Relay (W/DVOM)
      G00727724Courtesy of NISSAN MOTOR CO., U.S.A.
      1. Voltage: Battery voltage 

    OK or NG

    1. OK: Go to 8.
    2. NG: Go to 4.

  4. Check ICC Brake Switch Power Supply Circuit 
    1. Turn ignition switch OFF.
    2. Disconnect ICC brake switch. See Figure.
    3. Turn ignition switch ON.
    4. Check harness continuity between ICC brake switch terminal 2 and ground with CONSULT-II or tester.
      Fig 11: Testing Circuit Through ICC Brake Switch (W/DVOM)
      G00727726Courtesy of NISSAN MOTOR CO., U.S.A.

      Refer to wiring diagram. See Figure.

      1. Voltage: Battery voltage 
    5. Also check harness for short to ground and short to power.

    OK or NG

    1. OK: Go to 6.
    2. NG: Go to 5.

  5. Detect Malfunctioning Part 

    Check the following.

    • Fuse block (J/B) connector E201
    • 10A fuse
    • Harness for open or short between ICC brake switch and fuse

    1. Repair open circuit or short to ground or short to power in harness or connectors.
  6. Check ICC Brake Switch Input Signal Circuit-II 
    1. Turn ignition switch OFF.
    2. Check harness continuity between ICC brake switch terminal 2 and ICC brake hold relay terminal 3.
      1. Continuity should exist  .
    3. Also check harness for short to ground and short to power.

    OK or NG

    1. OK: Go to 7.
    2. NG: Repair open circuit or short to ground or short to power in harness or connectors.

  7. Check ICC Brake Switch 

    Refer to COMPONENT INSPECTION .

    1. OK: Go to 16.
    2. NG: Replace ICC brake switch.
  8. Check ICC Brake Switch Input Signal Circuit-III 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ICC brake hold relay terminal 4 and ECM terminal 108.
      1. Continuity should exist  .
    3. Also check harness for short to ground and short to power.

    OK or NG

    1. OK: Go to 10.
    2. NG: Go to 9.

  9. Detect Malfunctioning Part 

    Check the following.

    • Harness connectors E211. M41
    • Harness for open or short between ICC brake hold relay and ECM

    1. Repair open circuit or short to ground or short to power in harness or connectors.
  10. Check ICC Brake Hold Relay 

    Refer to COMPONENT INSPECTION .

    OK or NG

    1. OK: Go to 16.
    2. NG: Replace ICC brake hold relay.

  11. Check Stop Lamp Switch Power Supply Circuit 
    1. Turn ignition switch OFF.
    2. Disconnect stop lamp switch harness connector. See Figure.
    3. Check voltage between stop lamp switch terminal 1 and ground with CONSULT -II or tester.
      Fig 12: Testing Power To Stop Lamp Switch (DVOM)
      G00727728Courtesy of NISSAN MOTOR CO., U.S.A.
      1. Voltage: Battery voltage 

    OK or NG

    1. OK: Go to 13.
    2. NG: Go to 12.

  12. Detect Malfunctioning Part 

    Check the following.

    • Fuse block (J/B) connector E201
    • 10A fuse
    • Harness for open or short between stop lamp switch and battery

    1. Repair open circuit or short to ground in harness or connectors.
  13. Check Stop Lamp Switch Input Signal Circuit For Open And Short 
    1. Disconnect ECM harness connector.
    2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 2. Refer to wiring diagram. See WIRING DIAGRAM .
      1. Continuity should exist  .
    3. Also check harness for short to ground and short to power.

    OK or NG

    1. OK: Go to 15.
    2. NG: Go to 14.

  14. Detect Malfunctioning Part 

    Check the following.

    • Harness connectors E211, M41
    • Harness for open or short between ECM and stop lamp switch

    1. Repair open circuit or short to ground in harness or connectors.
  15. Check Stop Lamp Switch 

    Refer to COMPONENT INSPECTION 

    OK or NG

    1. OK: Go to 16.
    2. NG: Replace stop lamp switch.

  16. Check Intermittent Incident 

    Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

    1. Inspection end 
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