Nissan Sentra B18 (2020-2025) Service Manual: B2f71-23 Stop Lamp

Dtc Description

DTC Description

DTC DETECTION LOGIC

DTC No.	CONSULT screen items (Trouble diagnosis content)	DTC detecting condition
B2F71-23	Stop lamp (Stop lamp)	Diagnosis condition	When brake pedal is depressed
		Signal (terminal)	Brake pedal position switch signal
		Threshold	When brake pedal position switch signal is not input when brake pedal depressed.
		Diagnosis delay time	10 times or more

POSSIBLE CAUSE

• Harness or connectors

  (Brake pedal position switch circuit is short to battery)

• Brake pedal position switch

• Fuse

• BCM

FAIL-SAFE

—

Confirmation Procedure

Confirmation Procedure

1. PERFORM DTC CONFIRMATION PROCEDURE

   1. CONSULT

      1. Depress brake pedal 10 times or more.

      2. Ignition switch ON.

      3. Select “Self Diagnostic Result” mode of “BCM”.

   Is DTC 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. CHECK FUSE

   1. Check that the following fuse is not blown (open):

      Signal name	Fuse No.	Capacity
      Ignition power supply	3	10 A

   Is the fuse blown (open)?

   YES >>

   Replace the blown (open) fuse after replacing the cause of blown (open).

   NO >>

   GO TO 2.

2. CHECK BRAKE PEDAL POSITION SWITCH SIGNAL

   1. 1. Ignition switch OFF.

      2. Disconnect BCM connector.

      3. Ignition switch ON.

      4. Check voltage between BCM harness connector and ground.

         (+)		(–)	Condition	Voltage (Approx.)
         BCM
         Connector	Terminal
         M142	111	Ground	Brake pedal is not depressed	Battery voltage
         			Brake pedal is depressed	0 V

   Is the inspection normal?

   YES >>

   Replace BCM. Refer to Removal and Installation.

   NO >>

   GO TO 3.

3. CHECK BRAKE PEDAL POSITION SWITCH POWER SUPPLY CIRCUIT

   1. 1. Ignition switch OFF.

      2. Disconnect brake pedal position switch connector.

      3. Ignition switch ON.

      4. Check voltage between brake pedal position switch harness connector and ground.

         (+)		(–)	Voltage (Approx.)
         Brake pedal position switch
         Connector	Terminal
         E84	1	Ground	Battery voltage

   Is the inspection result normal?

   YES >>

   GO TO 4.

   NO >>

   Check harness for open or short between brake pedal position switch and fuse.

4. CHECK BRAKE PEDAL POSITION SWITCH SIGNAL CIRCUIT

   1. 1. Ignition switch OFF.

      2. Check continuity between brake pedal position switch harness connector and BCM harness connector.

         Brake pedal position switch		BCM		Continuity
         Connector	Terminal	Connector	Terminal
         E84	2	M142	111	Yes

      3. Check continuity between brake pedal position switch harness connector and ground.

         Brake pedal position switch		—	Continuity
         Connector	Terminal
         E84	2	Ground	No

   Is the inspection result normal?

   YES>>

   GO TO 5.

   NO>>

   Repair or replace harness.

5. CHECK BRAKE PEDAL POSITION SWITCH

   1. Refer to Component Inspection.

   Is the inspection result normal?

   YES >>

   Replace BCM. Refer to Removal and Installation.

   NO >>

   Replace brake pedal position switch. Refer to Exploded View.