Nissan Sentra B18 (2020-2025) Service Manual: Precautions

Precaution for Supplemental Restraint System (srs) "air Bag" and "seat Belt Pre-Tensioner"

Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT PRE-TENSIONER"

The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of collisions.

Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” sections of this Service Manual.

Warning:

Always observe the following items for preventing accidental activation:

• To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death in the event of a collision that would result in air bag inflation, it is recommended that all maintenance and repair be performed by an authorized NISSAN/INFINITI dealer.

• Improper repair, including incorrect removal and installation of the SRS, can lead to personal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag Module, see “SRS AIR BAG”.

• Never use electrical test equipment on any circuit related to the SRS unless instructed to in this Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or harness connectors.

PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS

Warning:

Always observe the following items for preventing accidental activation:

• When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition/power switch ON or engine running, never use air or electric power tools or strike near the sensor(s) with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly causing serious injury.

• When using air or electric power tools or hammers, always switch the ignition/power switch OFF, disconnect the 12V battery or batteries, and wait at least 3 minutes before performing any service.

Precaution for Handling High Pressure Fuel System

Precaution for Handling High Pressure Fuel System

• High pressure fuel system components are between high pressure fuel pump and fuel injector.

• Always release fuel pressure and never start the engine when performing removal and installation.

• When removing or installing parts without releasing fuel pressure, fuel may be splashed and, if fuel contacts skin or eyes, it may cause inflammation.

Special Cautions to Ensure the Safe Disposal of Sodium-Filled Valves

Special Cautions to Ensure the Safe Disposal of Sodium-filled Valves

Handling and disposal of sodium-filled valves requires special care and consideration. Under conditions such as breakage with subsequent contact with water, metal sodium which lines the inner portion of valve will react violently, forming sodium hydroxide and hydrogen which may result in an explosion. Sodium-filled valve is identified on the top of its stem as shown in illustration.

Identification mark of sodium-filled valve (A)
	Intake	: Not applicable
	Exhaust	: LBB

DEALER DISPOSAL INSTRUCTIONS

CAUTION:

• Use approved shatter-resistant eye protection when performing this procedure.

• Perform this and all subsequent disposal work procedures in an open room, away from flammable liquids. Keep a fire extinguisher, rated at least 10 ABC, in close proximity to the work area.

• Be sure to wear rubber gloves when performing the following operations.

• Make sure the resultant (high alkalinity) waste water does not contact your skin. If the waste water does contact you, wash the contacted area immediately with large quantities of water.

• Dealers should check their respective state and local regulations concerning any chemical treatment or waste water discharge permits which may be required to dispose of the resultant (high alkalinity) waste water.

1. Clamp valve stem in a vice.

2. The valve has a specially-hardened surface. To cut through it, first remove a half-round section, approximately 30 mm (1.18 in) long using air-powered grinder until black color is removed and silver color appears.

   

   (A)	: Black color
   (B)	: Silver color
   (c)	: 65 mm (2.56 in)
   (d)	: 35 mm (1.38 in)

3. Use hacksaw to cut through approximately half the diameter of valve stem. Make the serration at a point from the end of valve stem.

   

   (a)	: 50 mm (1.97 in)

4. Cover the serrated end of the valve with a large shop towel (A). Strike the valve face end with a hammer, separating it into two pieces.

   

5. Fill a bucket, such as a 20 (5-1/4 US gal, 4-3/8 Imp gal) oil can with at least 10 (2-5/8 US gal, 2-1/4 lmp gal) of water. Carefully place the already cut (serrated) valves into the water one-at-a-time using a set of large tweezers and quickly move away at least 2.7 m (9 ft).

6. The valves should be placed in a standing position as shown in the illustration to allow complete reaction. After the bubbling action has subsided, additional valves can be placed into the bucket allowing each subsequent chemical reaction to subside. However, no more than 8 valves should be placed in the same 10 (2-5/8 US gal, 2-1/4 lmp gal) amount of water. The complete chemical reaction may take as long as 4 to 5 hours. Remove the valves using a set of large tweezers after the chemical reaction has stopped. Afterwards, valves can be disposed as ordinary scrap.

   

   (A)	: Bucket [Such as 20 (5-1/4 US gal, 4-3/8 Imp gal) oil can]

Precautions for Engine Service

Precautions For Engine Service

DISCONNECTING FUEL PIPING

• Before starting work, check no fire or spark producing items are in the work area.

• Release fuel pressure before disconnecting and disassembly.

• After disconnecting pipes, plug openings to stop fuel leakage.

DRAINING ENGINE COOLANT

Drain engine coolant and engine oil when the engine is cooled.

INSPECTION, REPAIR AND REPLACEMENT

Before repairing or replacing, thoroughly inspect parts. Inspect new replacement parts in the same way, and replace if necessary.

REMOVAL AND DISASSEMBLY

• When instructed to use SST, use specified tools. Always be careful to work safely, avoid forceful or uninstructed operations.

• Exercise maximum care to avoid damage to mating or sliding surfaces.

• Dowel pins are used for several parts alignment. When replacing and reassembling parts with dowel pins, check that dowel pins are installed in the original position.

• Must cover openings of engine system with a tape or equivalent, to seal out foreign materials.

• Mark and arrange disassembly parts in an organized way for easy troubleshooting and reassembly.

• When loosening nuts and bolts, as a basic rule, start with the one furthest outside, then the one diagonally opposite, and so on. If the order of loosening is specified, do exactly as specified. Power tools may be used in the step.

ASSEMBLY AND INSTALLATION

• Use torque wrench to tighten bolts or nuts to specification.

• When tightening nuts and bolts, as a basic rule, equally tighten in several different steps starting with the ones in center, then ones on inside and outside diagonally in this order. If the order of tightening is specified, do exactly as specified.

• Replace with new gasket, packing, oil seal or O-ring.

• Thoroughly wash, clean, and air-blow each part. Carefully check engine oil or engine coolant passages for any restriction and blockage.

• Avoid damaging sliding or mating surfaces. Completely remove foreign materials such as cloth lint or dust. Before assembly, oil sliding surfaces well.

• After disassembling, or exposing any internal engine parts, change engine oil and replace oil filter with a new one.

• Release air within route when refilling after draining engine coolant.

• After repairing, start the engine and increase engine speed to check engine coolant, fuel, engine oil, and exhaust gases for leakage.

Parts Requiring Angle Tightening

Parts Requiring Angle Tightening

• Use the Tool for the final tightening of the following engine parts:

  Tool number

  : KV10112100 (BT-8653-A)

  • Camshaft sprocket (INT) bolt

  • Cylinder head bolts

  • Main bearing cap bolts

  • Connecting rod cap bolts

  • Crankshaft pulley bolt (No the angle wrench is required as bolt flange is provided with notches for angle tightening)

• Do not use a torque value for final tightening.

• The torque value for these parts are for a preliminary step.

• Ensure thread and seat surfaces are clean and coated with engine oil.

Liquid Gasket

Liquid Gasket

REMOVAL OF LIQUID GASKET SEALING

• After removing the bolts and nuts, separate the mating surface and remove the liquid gasket using Tool (A).

  

  Tool number (A)

  : KV10111100 (NI-37228)

  CAUTION:

  Be careful not to damage the mating surfaces.

• In areas where the cutter is difficult to use, use a plastic hammer to lightly tap (1) the cutter where the liquid gasket is applied. Use a plastic hammer to slide (2) the cutter by tapping on the side.

CAUTION:

Do not damage the mating surfaces.

LIQUID GASKET APPLICATION PROCEDURE

1. Using suitable tool (A), remove old liquid gasket adhering to the liquid gasket application surface and the mating surface.

   

   • Remove liquid gasket completely from the groove of the liquid gasket application surface, mounting bolts, and bolt holes.

2. Thoroughly clean the mating surfaces and remove adhering moisture, grease and foreign materials.

3. Attach liquid gasket tube to the suitable tool.

   

   Use Genuine Silicone RTV Sealant, or equivalent. Refer to Recommended Chemical Products and Sealants.

4. Apply liquid gasket without gaps to the specified location according to the specified dimensions.

   • If there is a groove for liquid gasket application, apply liquid gasket to the groove.

   • As for bolt holes (B), normally apply liquid gasket inside the holes. Occasionally, it should be applied outside the holes. Check to read the text of this manual.

     

     (A)	: Groove
     	: Inside

   • Within five minutes of liquid gasket application, install the mating component.

   • If liquid gasket protrudes, wipe it off immediately.

   • Do not retighten bolts or nuts after the installation.

   • After 30 minutes or more have passed from the installation, fill engine oil and engine coolant. Refer to Refilling and Refilling.

   CAUTION:

   If there are more specific instructions in the procedures contained in this manual concerning liquid gasket application, observe them.