Nissan Sentra B18 (2020-2025) Service Manual: Dtc Diagnosis Procedure

DTC Diagnosis Procedure

1. DETERMINE MALFUNCTION TYPE

   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”.

      5. Check DTC.

   Is DTC B272D–12 or 14 detected?

   YES>>

   12 – GO TO 2.

   YES>>

   14 – GO TO 3.

   NO>>

   Refer to Intermittent Incident.

2. CHECK SONAR BUZZER CIRCUIT SHORT TO BATTERY

   1. 1. Ignition switch ON.

      2. Check voltage between sonar control unit connector and ground.

         (+)		(–)	Voltage (Approx.)
         Sonar control unit
         Connector	Terminal
         B87	18	Ground	0 V
         	19

   Is the inspection result normal?

   YES >>

   GO TO 4.

   NO >>

   Repair or replace harness or connectors.

3. CHECK SONAR BUZZER CIRCUIT OPEN OR SHORT TO GROUND

   1. 1. Ignition switch OFF.

      2. Disconnect sonar control unit and sonar buzzer connectors.

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

         Sonar control unit		Sonar buzzer		Continuity
         Connector	Terminal	Connector	Terminal
         B87	18	M29	3	Yes
         	19		2

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

         Sonar control unit		—	Continuity
         Connector	Terminal
         B87	18	Ground	No
         	19

   Is the inspection result normal?

   YES >>

   GO TO 4.

   NO >>

   Repair or replace harness or connectors.

4. CHECK SONAR BUZZER CIRCUIT SIGNAL

   1. 1. Connect sonar control unit and sonar buzzer connectors.

      2. Ignition switch ON.

      3. Check signal between the terminals of sonar control unit connector.

         Sonar control unit			Condition	Voltage (Approx.)
         Connector	(+)	(–)
         	Terminal	Terminal
         B87	18	15	Obstacle detected	0 – 12 V (variable)

   Is the inspection result normal?

   YES >>

   Replace sonar buzzer. Refer to Removal and Installation.

   NO >>

   Replace sonar control unit. Refer to Removal and Installation.

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