2004 Nissan-Datsun Sentra SE-RFACTORY OEM SERVICE PROCEDURE

Check Security Horn Operation

WARNING: This page is about a different car, the 2004 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK SECURITY HORN CHIRP OPERATION 

    With CONSULT-II 

    1. Check security horn chirp "HORN" in "ACTIVE TEST" mode with CONSULT-II.
    2. Perform operation shown on display.

      Security horn should sound. 

    Without CONSULT-II 

    1. Disconnect BCM connector.
    2. Apply ground to BCM connector E204 terminal 127 (P/L).

      Security horn should sound. 

      Fig 1: Checking Security Horn Chirp Operation
      G00744205Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: Security horn alarm is OK.
    2. NG: GO TO 2.
  2. CHECK SECURITY HORN RELAY 

    Check security horn relay condition.

    OK or NG 

    1. OK: GO TO 3.
    2. NG: Replace security horn relay.
  3. CHECK POWER SUPPLY FOR SECURITY HORN RELAY 
    1. Disconnect security horn relay connector.
    2. Check voltage between security horn relay connector E77 terminal 2 (Y/B) and ground.

      2 (Y/B) - Ground: Battery voltage 

    OK or NG 

    1. OK: GO TO 4.
    2. NG: Check the following.
    • 10A fuse [No. 78, located in the fuse, fusible link and relay block (J/B)]
    • Harness for open or short between security horn relay and fuse.
    Fig 2: Checking Power Supply For Security Horn Relay
    G00744206Courtesy of NISSAN MOTOR CO., U.S.A.
  4. CHECK SECURITY HORN RELAY CIRCUIT 
    1. Disconnect BCM and security horn relay connector.
    2. Check continuity between BCM connector E204 terminal 127 (P/L) and security horn relay connector E77 terminal 1 (P/L).

      127 (p/L) - 1 (P/L) :Continuity should exist. 

      Fig 3: Checking Security Horn Relay Circuit
      G00744207Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: GO TO 5.
    2. NG: Repair or replace harness.
  5. CHECK SECURITY HORN RELAY CIRCUIT 
    1. Disconnect security horn relay and security horn connector.
    2. Check continuity between security horn relay connector E77 terminal 3 (P/B) and security horn connector E30 terminal 1 (P/B).

      3 (P/B) - 1 (P/B) :Continuity should exist. 

      Fig 4: Checking Security Horn Relay Circuit
      G00744208Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    1. OK: Replace security horn.
    2. NG: Repair or replace harness.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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