LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2008 >> QX56 AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - DTCS P1148 To P2A03 >> DTC P1550: Battery Current Sensor >> Diagnosis Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis Procedure

  1. CHECK GROUND CONNECTIONS
    1. Turn ignition switch OFF.
    2. Loosen and retighten ground screws on the body.

      Refer to "GROUND INSPECTION ".

      Fig 1: Identifying Body Ground Screw
      G05739606Courtesy of NISSAN MOTOR CO., U.S.A.

    OK or NG 

    OK: GO TO 2.

    NG: Repair or replace ground connections.

  2. CHECK BATTERY CURRENT SENSOR POWER SUPPLY CIRCUIT
    1. Disconnect battery current sensor (1) harness connector.
    2. Turn ignition switch ON.

      <=: Vehicle front

      Fig 2: Identifying Battery Current Sensor
      G05739607Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between battery current sensor terminal 1 and ground with CONSULT-III or tester.

      Voltage: Approximately 5V 

    OK or NG 

    OK: GO TO  4.

    NG: GO TO 3.

    Fig 3: Checking Voltage Between Battery Current Sensor Terminal 1 And Ground
    G05739608Courtesy of NISSAN MOTOR CO., U.S.A.
  3. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors E5, F14
    • Harness for open or short between battery current sensor and ECM

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

  4. CHECK BATTERY CURRENT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
    1. Turn ignition switch OFF.
    2. Disconnect ECM harness connector.
    3. Check harness continuity between battery current sensor terminal 2 and ECM terminal 67.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    4. Also check harness for short to ground and short to power.

    OK or NG 

    OK: GO TO  6.

    NG: GO TO 5.

  5. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors E5, F14
    • Harness for open or short between battery current sensor and ECM

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

  6. CHECK BATTERY CURRENT SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
    1. Check harness continuity between battery current sensor terminal 3 and ECM terminal 71.

      Refer to WIRING DIAGRAM .

      Continuity should exist. 

    2. Also check harness for short to ground and short to power.

    OK or NG 

    OK: GO TO  8.

    NG: GO TO 7.

  7. DETECT MALFUNCTIONING PART

    Check the following.

    • Harness connectors E2, F32
    • Harness for open or short between battery current sensor and ECM

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

  8. CHECK BATTERY CURRENT SENSOR

    Refer to "COMPONENT INSPECTION ".

    OK or NG 

    OK: GO TO 9.

    NG: Replace battery negative cable assembly.

  9. CHECK INTERMITTENT INCIDENT

    Refer to "HOW TO CHECK TERMINAL " and "INTERMITTENT INCIDENT ".

    INSPECTION END 

scientia non olet · About LEMON Manuals