Nissan Sentra B18 (2020-2025) Service Manual: Back-Up Lamp Relay Circuit

Component Function Check

1. CHECK BACK-UP LAMP OPERATION

   1. 1. Ignition switch ON.

      2. With operating the shift selector, check that the back-up lamp is turned ON.

         Shift selector R position	: Back-up lamp ON
         Shift selector other than R position	: Back-up lamp OFF

   Is the inspection result normal?

   YES >>

   Back-up lamp circuit is normal.

   NO >>

   Refer to Diagnosis Procedure.

Diagnosis Procedure

1. CHECK FUSE

   1. 1. Ignition switch OFF.

      2. Check if the following fuse is not blown:

         Signal name	Location	Fuse No.	Capacity
         Battery power supply (back-up lamp relay)	IPDM E/R	89	10 A

   Is the fuse blown (open)?

   YES >>

   Replace the blown fuse after repairing the affected circuit.

   NO >>

   GO TO 2.

2. CHECK BACK-UP LAMP RELAY POWER

   1. 1. Disconnect back-up lamp relay connector.

      2. Ignition switch ON.

      3. Check voltage between back-up lamp relay harness connector and ground.

         Back-up lamp relay		—	Voltage (Approx.)
         Connector	Terminal
         F61	7	Ground	Battery voltage
         	8

   Is the inspection result normal?

   YES >>

   GO TO 3.

   NO >>

   Repair or replace harness or connectors.

3. CHECK BACK-UP LAMP RELAY CONTROL SIGNAL VOLTAGE

   1. 1. Connect back-up lamp relay connector.

      2. Check voltage between TCM harness connector and ground.

         +		—	Condition		Voltage (Approx.)
         TCM
         Connector	Terminal
         F23	29	Ground	Shift selector	R position	0 V
         				Other than R position	Battery voltage

   Is the inspection result normal?

   YES >>

   GO TO 5

   NO >>

   GO TO 4.

4. CHECK BACK-UP LAMP RELAY CONTROL SIGNAL CIRCUIT

   1. 1. Ignition switch OFF.

      2. Disconnect TCM connector and back-up lamp relay connector.

      3. Check continuity between TCM harness connector and back-up lamp relay harness connector.

         TCM		Back-up lamp relay		Continuity
         Connector	Terminal	Connector	Terminal
         F23	29	F61	9	Yes

      4. Check continuity between TCM harness connector and ground.

         TCM		Ground	Continuity
         Connector	Terminal
         F23	29		No

   Is the inspection result normal?

   YES >>

   Replace TCM. Refer to Removal and Installation.

   NO >>

   Repair or replace harness or connectors.

5. CHECK BACK-UP LAMP RELAY

   1. Check back-up lamp relay. Refer to Component Inspection.

   Is the inspection result normal?

   YES >>

   GO TO 6.

   NO >>

   Replace back-up lamp relay.

6. CHECK BACK-UP LAMP POWER SUPPLY CIRCUIT

   1. 1. Ignition switch OFF.

      2. Disconnect back-up lamp relay connector rear combination lamp LH (trunk lid side) connector and rear combination lamp RH (trunk lid side) connector.

      3. Check continuity between back-up lamp relay harness connector and rear combination lamp (trunk lid side) harness connector.

         Back-up lamp relay			Rear combination lamp (trunk lid side)		Continuity
         Connector		Terminal	Connector	Terminal
         RH	F61	6	B75	2	Yes
         LH			B88

      4. Check continuity between back-up lamp relay harness connector and ground.

         Back-up lamp relay		Ground	Continuity
         Connector	Terminal
         F61	6		No

   Is the inspection result normal?

   YES>>

   GO TO 7.

   NO>>

   Repair or replace harness or connectors.

7. CHECK BACK-UP LAMP GROUND CIRCUIT

   1. Check continuity between rear combination lamp (trunk lid side) harness connector and ground.

      Rear combination lamp (trunk lid side)			—	Continuity
      Connector		Terminal
      RH	B75	4	Ground	Yes
      LH	B88

   Is the inspection result normal?

   YES >>

   Replace corresponding rear combination lamp (trunk lid side) bulb. Refer to Removal and Installation.

   NO >>

   Repair or replace harness or connectors.

Component Inspection

1. CHECK BACK-UP LAMP RELAY

   1. 1. Ignition switch OFF.

      2. Disconnect back-up lamp relay connector.

      3. Check continuity between back-up lamp relay terminals.

      Back-up lamp relay		Condition	Continuity
      Terminals
      7	8	12 V direct current supply between terminals 8 and 9.	Yes
      		No current supply	No

   Is the inspection result normal?

   YES >>

   Inspection End.

   NO >>

   Replace back-up lamp relay.

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