Nissan Sentra Service Manual: Symptom diagnosis
OVERHEATING CAUSE ANALYSIS
Troubleshooting Chart
| Symptom | Check items | |||
| Cooling system parts malfunction | Poor heat transfer | Water pump malfunction | Worn or loose drive belt | — |
| Thermostat stuck closed | Engine coolant circulation | |||
| Damaged fins | Dust contamination or rock clogging | |||
| Mechanical damage | ||||
| Clogged radiator cooling tube | Excess foreign material (rust, dirt, sand, etc.) | |||
| Reduced air flow | Cooling fan does not operate | Fan shroud and motor as- High resistance to fan rota- sembly | — | |
| High resistance to fan rotation | ||||
| Damaged fan blades | ||||
| Damaged radiator shroud | — | Radiator shroud | — | |
| Improper engine coolant mixture ratio | — | Engine coolant viscosity | — | |
| Poor engine coolant quality | — | Periodic maintenance | — | |
| Insufficient engine coolant | Engine coolant leaks | Cooling hose | Loose clamp | |
| Cracked hose | ||||
| Water pump | Poor sealing | |||
| Radiator cap | Loose | |||
| Poor sealing | ||||
| Radiator | O-ring for damage, deterioration or improper fitting | |||
| Cracked radiator tank | ||||
| Cracked radiator core | ||||
| Reservoir tank | Cracked reservoir tank | |||
| Overflowing reservoir tank | Exhaust gas leaks into cooling system | Cylinder head deterioration | ||
| Cylinder head gasket deterioration | ||||
| Except cooling system parts malfunction |
— |
Overload on engine | Abusive driving | High engine rpm under no load |
| Driving in low gear for extended time | ||||
| Driving at extremely high speed | ||||
| Powertrain system malfunction |
— |
|||
| Installed improper size wheels and tires | ||||
| Dragging brakes | ||||
| Improper ignition timing | ||||
| Blocked or restricted air flow | Blocked radiator grille | Installed car brassiere | — | |
| Blocked bumper | ||||
| Blocked radiator | ||||
| Blocked condenser | Mud contamination or paper clogging | |||
| Installed large fog lamp | ||||
System description
DESCRIPTION
Engine Cooling System Schematic
CVT Models
Radiator
Water inlet
Reservoir tank
Thermostat
Engine oil cooler
Thermostat housing
Water pump
Cylinder head
Cylinder b ...
Periodic maintenance
ENGINE COOLANT
System Inspection
WARNING:
Do not remove the radiator cap when the engine is hot. Serious
burns could occur from high pressure
engine coolant escaping from the radiator.
Wr ...
Other materials:
Ecm branch line circuit
Diagnosis procedure
1.Check connector
Turn the ignition switch off.
Disconnect the battery cable from the negative terminal.
Check the terminals and connectors of the ecm for damage, bend and loose
connection (unit side and
connector side).
Is the inspection result normal?
Yes > ...
A/c auto amp. Connection recognition signal circuit
Description
A/c auto amp. Transmits the a/c auto amp. Connection recognition signal to
the combination meter
Diagnosis procedure (with manual a/c)
Regarding wiring diagram information, refer to mwi-28, "wiring diagram".
1.Check a/c auto amp. Connection recognition signal
Turn ig ...
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 collision. Information necessary to service the system ...
