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

Diagnosis Procedure

1. CHECK FUSE

   1. 1. Ignition switch OFF.

      2. Check that any of the following fuses are not blown (open):

         Signal name	Fuse No.	Capacity
         Ignition switch ON power supply	6	10 A
         Battery power supply	23	10 A

   Is the inspection result normal?

   YES >>

   GO TO 2.

   NO >>

   Replace the blown fuse after repairing the affected circuit.

2. CHECK HEATED SEAT LH RELAY POWER SUPPLY

   1. 1. Disconnect heated seat LH relay connector.

      2. Ignition switch ON.

      3. Check voltage between heated seat LH relay harness connector and ground.

         (+)			(-)	Voltage (Approx.)
         Heated seat LH relay
         Connector		Terminal
         High	M150	1	Ground	Battery voltage
         		5
         Low	M6	1
         		5

   Is the inspection result normal?

   YES >>

   GO TO 3.

   NO >>

   Repair or replace harness.

3. CHECK HEATED SEAT LH RELAY CONTROL SIGNAL CIRCUIT

   1. 1. Ignition switch OFF.

      2. Disconnect A/C auto amp. connector (with auto A/C) or A/C amp. connector (with manual A/C).

      3. Check continuity between heated seat LH relay harness connector and A/C auto amp. (with auto A/C) or A/C amp. (with manual A/C) harness connector.

         With auto A/C

         Heated seat LH relay			A/C auto amp.		Continuity
         Connector		Terminal	Connector	Terminal
         High	M150	2	M34	55	Yes
         Low	M6			75

         With manual A/C

         Heated seat LH relay			A/C amp.		Continuity
         Connector		Terminal	Connector	Terminal
         High	M150	2	M82	55	Yes
         Low	M6			75

      4. Check continuity between A/C auto amp. (with auto A/C) or A/C amp. (with manual A/C) harness connector and ground.

         With auto A/C

         A/C auto amp.		(-)	Continuity
         Connector	Terminal
         M34	55	Ground	No
         	75

         With manual A/C

         A/C amp.		(-)	Continuity
         Connector	Terminal
         M82	55	Ground	No
         	75

   Is the inspection result normal?

   YES >>

   GO TO 4.

   NO >>

   Repair or replace harness.

4. CHECK HEATED SEAT LH RELAY

   1. Check heated seat LH relay.

      Refer to Component Inspection.

   Is the inspection result normal?

   YES>>

   Replace A/C auto amp. (with auto A/C) or A/C amp. (with manual A/C). Refer to Removal and Installation (with auto A/C) or Removal and Installation (with manual A/C).

   NO>>

   Replace corresponding heated seat LH relay.

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