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Nissan Sentra B18 (2020-2025) Service Manual: B273b Rear Sensor Power

Dtc Description

DTC Description

DTC DETECTION LOGIC

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detection condition

B273B–11

REAR SENSOR POWER

(Rear sensor power)

Diagnosis condition

Ignition switch ON

Signal (terminal)

Rear sensor power supply (terminal 23)

Threshold

Rear sensor power supply is short to ground

Diagnosis delay time

4 seconds or more

B273B–12

Diagnosis condition

Ignition switch ON

Signal (terminal)

Rear sensor power supply (terminal 23)

Threshold

Rear sensor power supply is short to voltage

Diagnosis delay time

4 seconds or more

B273B–87

Diagnosis condition

Ignition switch ON

Signal (terminal)

Rear sensor power supply (terminal 23)

Threshold

Connection error is detected between sonar control unit and rear sonar sensors

Diagnosis delay time

4 seconds or more

POSSIBLE CAUSE

  • Harness or connectors

  • Sonar control unit

FAIL-SAFE

Obstacle detection function is deactivated

Dtc Confirmation Procedure

DTC Confirmation Procedure

  1. DTC CONFIRMATION PROCEDURE

    1. CONSULT

      1. Ignition switch ON.

      2. Ignition switch OFF and wait at least 30 seconds.

      3. Ignition switch ON and wait at least 2 seconds or more.

      4. Select “Self Diagnostic Result” mode of “SONAR”.

    Is DTC B273B detected?

    YES >>

    Refer to DTC Diagnosis Procedure.

    NO >>

    To check malfunction symptom before repair: Refer to Intermittent Incident.

    NO >>

    Confirmation after repair: Inspection End.

Dtc Diagnosis Procedure

DTC Diagnosis Procedure

  1. DETERMINE MALFUNCTION TYPE

    1. CONSULT

      1. Ignition switch ON.

      2. Select “Self Diagnostic Result” mode of “SONAR”.

      3. Check the DTC.

    Is DTC B273B–11, 12 or 87 detected?

    YES >>

    11 – GO TO 2.

    YES >>

    12 – GO TO 3.

    YES >>

    87 – GO TO 4.

    NO >>

    Refer to Intermittent Incident.

  2. CHECK REAR SENSOR POWER SUPPLY CIRCUIT FOR SHORT TO GROUND

      1. Ignition switch OFF.

      2. Disconnect sonar control unit and all rear sonar sensor connectors.

      3. Check continuity between sonar control unit connector and ground.

        Sonar control unit

        Continuity

        Connector

        Terminal

        B87

        23

        Ground

        No

    Is the inspection result normal?

    YES >>

    Replace sonar control unit. Refer to Removal and Installation.

    NO >>

    Repair or replace harness or connectors.

  3. CHECK REAR SENSOR POWER SUPPLY FOR SHORT TO VOLTAGE

      1. Ignition switch OFF.

      2. Disconnect sonar control unit and all rear sonar sensor connectors.

      3. Ignition switch ON.

      4. Check the voltage between sonar control unit connector and ground.

        (+)

        (-)

        Voltage

        (Approx.)

        Sonar control unit

        Connector

        Terminal

        B87

        23

        Ground

        0 V

    Is the inspection result normal?

    YES >>

    Replace sonar control unit. Refer to Removal and Installation.

    NO >>

    Repair or replace harness or connectors.

  4. CHECK SONAR CONTROL UNIT AND REAR SENSOR CONNECTORS

    1. Check the terminals and connectors of each rear sonar sensor and sonar control unit for damage, bends and looseness.

    Is the inspection result normal?

    YES >>

    GO TO 5.

    NO >>

    Repair or replace harness or connectors.

  5. CHECK REAR SENSOR POWER SUPPLY CIRCUIT FOR OPEN

      1. Ignition switch OFF.

      2. Disconnect sonar control unit and all rear sonar sensor connectors.

      3. Check continuity between sonar control unit connector and rear sonar sensor connectors.

        Sonar control unit

        Rear sonar sensors

        Continuity

        Connector

        Terminal

        Connector

        Terminal

        B87

        23

        B402 (rear sonar sensor LH outer)

        3

        Yes

        B401 (rear sonar sensor RH outer)

        B403 (rear sonar sensor LH inner)

        B404 (rear sonar sensor RH inner)

    Is the inspection result normal?

    YES >>

    GO TO 6.

    NO >>

    Repair or replace harness or connectors.

  6. CHECK INTERMITTENT INCIDENT

    1. Perform intermittent incident. Refer to Intermittent Incident.

    Is the inspection result normal?

    YES >>

    Replace sonar control unit. Refer to Removal and Installation.

    NO >>

    Repair or replace the applicable malfunctioning components.

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