
DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK COOLING FAN OPERATION.
1. Turn ignition switch ``OFF''.
2. Turn ignition switch ``ON''.
3. Perform ``COOLING FAN'' in
``ACTIVE TEST'' mode with
CONSULT and make sure that
cooling fan operates when touch-
ing ``ON''.
--------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------
2. Disconnect engine coolant tem-
perature sensor harness connec-
tor.
3. Connect 150Wresistor to engine
coolant temperature sensor har-
ness connector.
4. Start engine and make sure that
cooling fan operates.
NG
cOK
Go to``CHECK COOL-
ING SYSTEM FOR LEAK'',
EC-119.
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect cooling fan relay-1.
3. Turn ignition switch ``ON''.
4. Check voltage between terminals
V2,
V5and ground with CONSULT or tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+10A fuse
+30A fusible link
+Harness for open or short
between cooling fan
relay-1 and fuse
+Harness for open or short
between cooling fan
relay-1 and battery
If NG, repair harness or
connectors.
CHECK GROUND CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect cooling fan motor harness
connector.
3. Check harness continuity between
relay terminal
V3and motor termi-
nals
V1,V3.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
4. Check harness continuity between
motor terminals
V2,V4and body
ground.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Repair open circuit or short
to ground or short to power
in harness or connectors.
jA
SEF758V
SEF979S
SEF690V
SEF759V
SEF691V
.
.
.
.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)
Cooling Fan (Overheat) (Cont'd)
EC-117

CHECK COOLING SYSTEM FOR LEAK.
Apply pressure to the cooling system with
a tester, and check if the pressure drops.
Testing pressure:
157 kPa (1.57 bar, 1.6 kg/cm
2, 23 psi)
Pressure should not drop.
CAUTION:
Higher than the speci®ed pressure may
cause radiator damage.
OK
cNG
Check the following for
leak.
+Hose
+Radiator
+Water pump
Refer to LC section (``Water
Pump'').
CHECK RADIATOR CAP.
Apply pressure to cap with a tester.
Radiator cap relief pressure:
78 - 98 kPa (0.78 - 0.98 bar, 0.8 - 1.0
kg/cm
2, 11 - 14 psi)
OK
cNG
Replace radiator cap.
CHECK THERMOSTAT.
1. Check valve seating condition at normal
room temperatures.
It should seat tightly.
2. Check valve opening temperature and
valve lift.
Valve opening temperature:
82ÉC (180ÉF) [standard]
Maximum valve lift:
More than 10 mm/95ÉC
(0.39 in/203ÉF)
3. Check if valve is closed at 5ÉC (9ÉF)
below valve opening temperature.
For details, refer to LC section (``Thermo-
stat'').
OK
cNG
Replace thermostat.
Check engine coolant temperature sensor.
Refer to ``COMPONENT INSPECTION'',
EC-82.
OK
cNG
Replace engine coolant
temperature sensor.
If the cause cannot be isolated, go to
``MAIN 12 CAUSES OF OVERHEATING''
on next page.
INSPECTION END
Perform FINAL CHECK by the following procedure after repair
is completed.
1. Warm up engine. Run the vehicle for at least 20 minutes. Pay
attention to engine coolant temperature gauge on the instrument
panel. If the reading shows an abnormally high temperature,
another part may be malfunctioning.
2. Stop vehicle and let engine idle. Check the intake and exhaust
systems for leaks by listening for noise or visually inspecting the
components.
3. Allow engine to cool and visually check for oil and coolant leaks.
Then, perform ``OVERALL FUNCTION CHECK''.
SLC754AA
SLC755AB
SLC343
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)
Cooling Fan (Overheat) (Cont'd)
EC-119

MAIN 12 CAUSES OF OVERHEATING
Engine Step Inspection item Equipment Condition Reference page
OFF 1+Blocked radiator
+Blocked radiator grille
+Blocked bumper+Visual No blocking Ð
2+Coolant mixture+Coolant tester 50 - 50% coolant mixture See ``RECOMMENDED
FLUIDS AND LUBRI-
CANTS'' in MA section.
3+Coolant level+Visual Coolant up to MAX level
in reservoir tank and
radiator ®ller neckSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
4+Radiator cap+Pressure tester 78 - 98 kPa
(0.78 - 0.98 bar, 0.8 - 1.0
kg/cm
2, 11 - 14 psi)See ``System Check''
``ENGINE COOLING
SYSTEM'' in LC section.
ON*
25+Coolant leaks+Visual No leaks See ``System Check''
``ENGINE COOLING
SYSTEM'' in LC section.
ON*
26+Thermostat+Touch the upper and
lower radiator hosesBoth hoses should be hot See ``Thermostat'' and
``Radiator'', ``ENGINE
COOLING SYSTEM'' in
LC section.
ON*
17+Cooling fan+CONSULT Operating See ``TROUBLE DIAG-
NOSIS FOR DTC 28'',
EC-113.
OFF 8+Combustion gas leak+Color checker chemical
tester 4 Gas analyzerNegative Ð
ON*
39+Coolant temperature
gauge+Visual Gauge less than 3/4
when drivingÐ
+Coolant over¯ow to res-
ervoir tank+Visual No over¯ow during driving
and idlingSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
OFF*
410+Coolant return from res-
ervoir tank to radiator+Visual Should be initial level in
reservoir tankSee ``ENGINE MAINTE-
NANCE'' in MA section.
OFF 11+Cylinder head+Straight gauge feeler
gauge0.1mm (0.004 in) Maxi-
mum distortion (warping)See ``Inspection'', ``CYL-
INDER HEAD'' in EM
section.
12+Cylinder block and pis-
tons+Visual No scuffing on cylinder
walls or pistonSee ``Inspection'', ``CYL-
INDER BLOCK'' in EM
section.
*1: Turn the ignition switch ON.
*2: Engine running at 3,000 rpm for 10 minutes.
*3: Drive at 90 km/h (55 MPH) for 30 minutes and then let idle for 10 minutes.
*4: After 60 minutes of cool down time.
For more information, refer to ``OVERHEATING CAUSE ANALYSIS'' in LC section.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)
Cooling Fan (Overheat) (Cont'd)
EC-120

System Description
This unit displays the following items:
+Earth magnetism and heading direction of vehicle.
+Outside air temperature.
+Caution for frozen road surfaces.
OUTSIDE TEMPERATURE DISPLAY
Push the switch when the ignition key is in the ``ACC'' or ``ON'' position. The outside temperature will be dis-
played in ``ÉF''.
+Selecting the indication range
Push the switch to change from ``ÉF'' to ``ÉC''.
+When the outside temperature drops below freezing point, ICE is displayed on the unit.
+When the outside temperature is between 55ÉC (130ÉF) and 70ÉC (158ÉF), the display shows 55ÉC
(130ÉF).
+When the outside temperature is lower than þ30ÉC (þ20ÉF) or higher than 70ÉC (158ÉF), the display shows
only ``- - -'' though it is operating. This is not a problem.
+The indicated temperature on the thermometer is not readily affected by engine heat. It changes only when
one of the following conditions is present.
a) The temperature detected by the ambient air temperature sensor is lower than the indicated temperature
on the thermometer.
b) The difference in temperature detected during a period of 40 seconds is less than 1ÉC (1.8ÉF) when vehicle
speed has been greater than 24 km/h (15 MPH) for more than 100 seconds.
(This is to prevent the indicated temperature from being affected by engine heat or cooling fan operation
during low-speed driving.)
c) The ignition key has been turned to the ``OFF'' position for more than 4 hours. (The engine is cold.)
DIRECTION DISPLAY
Push the switch when the ignition key is in the ``ACC'' or ``ON'' position. The direction will be displayed.
SEL713U
COMPASS AND THERMOMETER
EL-116

Use the chart below to ®nd out what each wiring diagram code
stands for.
Code Section Wiring Diagram Name
A/C,A HA Auto Air Conditioner
A/C CUT EC Air Conditioner Cut Control
A/C,M HA Manual Air Conditioner
A/T AT A/T
AAC/V EC IACV-AAC Valve
ABS BR Anti-lock Brake System
ACC/SW EC Accelerator Switch (FC)
ACL/SW EC Accelerator Position Switch
ADJRES EC Adjustment Resistor
APS EC Accelerator Position Sensor
ASCD EL Automatic Speed Control Device
AT/C EC A/T Control
AUDIO EL Audio
BACK/L EL Back-up Lamp
BCDD EC BCDD System
CD/CHG EL CD Auto Changer
CHARGE EL Charging System
CHIME EL Warning Chime
CHOKE EC Automatic Choke
CIGAR EL Cigarette Lighter
CKPS EC Crankshaft Position Sensor (OBD)
CLOCK EL Clock
CMPS EC Camshaft Position Sensor
COMPAS EL Compass and Thermometer
COOL/B HA Cool Box
COOL/F EC Cooling Fan Control
CORNER EL Cornering Lamp
CSPS EC Control Sleeve Position Sensor
D/LOCK EL Power Door Lock
DEICER EL Wiper Deicer
DEF EL Rear Window Defogger
DIFF/L PD Differential Lock Control System
DTRL ELHeadlamp Ð With Daytime Light
System
ECTS EC Engine Coolant Temperature Sensor
EGRC/V EC EGRC-Solenoid Valve
F/FOG EL Front Fog Lamp
F/PUMP EC Fuel Pump
FCUT EC Fuel Cut Solenoid Valve
FICD EC IACV-FICD Solenoid Valve
FTS EC Fuel Temperature SensorCode Section Wiring Diagram Name
GLOW EC Quick Glow System
GOVNR EC Electric Governor
H/AIM EL Headlamp Aiming Control System
H/LAMP EL Headlamp
HEATUP EC Heat up Switch
HLC EL Headlamp Cleaner
HORN EL Horn
HSEAT EL Heated Seat
IATS EC Intake Air Temperature Sensor
IC/FAN EC Charge Air Cooler Fan
IGN EC Ignition System
IGN/SG EC Ignition Signal
ILL EL Illumination
INJECT EC Injector
INT/L EL Spot, Vanity Mirror Lamps
KS EC Knock Sensor
MAFS EC Mass Air Flow Sensor
MAIN ECMain Power Supply and Ground Cir-
cuit
METER ELSpeedometer, Tachometer, Temp.,
Oil and Fuel Gauges
MIL/DL EC Mil and Data Link Connectors
MIRROR EL Door Mirror
MULTI EL Multi-remote Control System
NATS EL Nissan Anti-Theft System
NLS EC Needle Lift Sensor
P/ANT EL Power Antenna
PLA EC Partial Load Advance Control
PNP/SW EC Park/Neutral Position Switch
POWER EL Power Supply Routing
PST/SW EC Power Steering Oil Pressure Switch
R/COOL HA Rear Cooler System
R/FOG EL Rear Fog Lamp
R/HEAT HA Rear Heater System
ROOM/L EL Interior Room Lamp
S/LOCK EL Power Door Lock Ð Super Lock
S/SIG EC Start Signal
S/TANK FE Sub Fuel Tank Control System
SEAT EL Power Seat
SROOF EL Sunroof
SRS RS Supplemental Restraint System
WIRING DIAGRAM CODES (CELL CODES)
EL-315

NVH Troubleshooting Chart Ð Engine Noise
Use the chart below to help you ®nd the cause of the problem.
1. Locate the area where noise occurs.
2. Con®rm the type of noise.
3. Specify the operating condition of engine.
4. Check speci®ed noise source.
If necessary, repair or replace these parts.
Location of
noiseType of
noiseOperating condition of engine
Source of
noiseCheck itemReference
page Before
warm-upAfter
warm-upWhen
startingWhen
idlingWhen
racingWhile
driving
To p o f
engine
Rocker
cover
Cylinder
headTicking or
clickingCAÐABÐTappet
noiseValve clearance EM-41
Rattle C A Ð A B CCamshaft
bearing
noiseCamshaft journal clearance
Camshaft runoutEM-37
Crankshaft
pulley
Cylinder
block (Side
of engine)
Oil panSlap or
knockÐAÐB BÐPiston pin
noisePiston and piston pin clear-
ance
Connecting rod bushing
clearanceEM-47, 53
Slap or rap A Ð Ð B B APiston slap
noisePiston-to-bore clearance
Piston ring side clearance
Piston ring end gap
Connecting rod bend and
torsionEM-48, 49
Knock A B C B B BConnecting
rod bearing
noiseConnecting rod bushing
clearance (Small end)
Connecting rod bearing
clearance (Big end)EM-52, 53
Knock A B Ð A B CMain bear-
ing noiseMain bearing oil clearance
Crankshaft runoutEM-51
Timing belt
coverWhine or
hissingCAÐAAÐTiming belt
noise (too
tight)
Loose timing belt
Belt contacting caseEM-18
Clatter A B Ð C A ÐTiming belt
noise (too
loose)
Front of
engineSqueaking
or ®zzingABÐBÐCOther drive
belts
(Sticking or
slipping)Drive belts de¯ection
*1
CreakingABABABOther drive
belts (Slip-
ping)Idler pulley bearing operation
Squall
CreakABÐBABWater pump
noiseWater pump operation *2
A: Closely related B: Related C: Sometimes related Ð: Not related
*1: MA section (``Checking Drive Belts'', ``ENGINE MAINTENANCE'')
*2: LC section (``Water Pump Inspection'', ``ENGINE COOLING SYSTEM'')
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
EM-8

HEATER &
AIR CONDITIONER
SECTION
HA
CONTENTS
MANUAL AND AUTO
PRECAUTIONS AND PREPARATION............................1
Supplemental Restraint System (SRS) ``AIR
BAG'' and ``SEAT BELT PRE-TENSIONER'' ...............1
Precautions for Working with HFC-134a (R-134a) .....1
General Refrigerant Precautions .................................2
Precautions for Refrigerant Connection ......................2
Precautions for Servicing Compressor ........................6
Special Service Tools ..................................................6
HFC-134a (R-134a) Service Tools and
Equipment ....................................................................7
Precautions for Service Equipment .............................9
DESCRIPTION............................................................... 11
Refrigeration Cycle .................................................... 11
Component Layout ....................................................12
Discharge Air Flow.....................................................13
REAR HEATER
TROUBLE DIAGNOSES...............................................14
Wiring Diagram Ð R/HEAT Ð/LHD Models .............14
Wiring Diagram Ð R/HEAT Ð/RHD Models .............15
MANUAL
DESCRIPTION...............................................................16
System Description ....................................................16
Control Operation ......................................................16
TROUBLE DIAGNOSES...............................................17
Component Location..................................................17
Wiring Diagram Ð A/C, M Ð ....................................19
How to Perform Trouble Diagnoses for Quick
and Accurate Repair ..................................................21
Operational Check .....................................................22
Intake Door Motor ......................................................24
Blower Motor..............................................................28
Insufficient Cooling ....................................................32
Trouble Diagnoses for Abnormal Pressure ...............36
Insufficient Heating ....................................................39Air Outlet ....................................................................41
Magnet Clutch............................................................43
Noise ..........................................................................48
AUTO
DESCRIPTION...............................................................49
Introduction ................................................................49
Features .....................................................................49
Overview of Control System ......................................52
Control Operation ......................................................53
TROUBLE DIAGNOSES...............................................55
Component Location..................................................55
Circuit Diagram ..........................................................57
Wiring Diagram Ð A/C, A Ð .....................................58
Auto Amp. Terminals and Reference Value...............61
Self-diagnosis ............................................................63
How to Perform Trouble Diagnoses for Quick
and Accurate Repair ..................................................69
Operational Check .....................................................70
A/C System ................................................................73
Mode Door Motor.......................................................75
Air Mix Door Motor ....................................................79
Intake Door Motor ......................................................82
Blower Motor..............................................................86
Magnet Clutch............................................................92
Insufficient Cooling ....................................................98
Insufficient Heating ....................................................99
Noise ........................................................................100
Self-diagnosis ..........................................................101
Memory Function .....................................................102
Ambient Sensor .......................................................103
In-vehicle Sensor .....................................................105
Sunload Sensor .......................................................107
Intake Sensor........................................................... 110
HA

General Refrigerant Precautions
WARNING:
+Do not release refrigerant into the air. Use approved recovery/recycling equipment to capture the
refrigerant every time an air conditioning system is discharged.
+Always wear eye and hand protection (goggles and gloves) when working with any refrigerant or
air conditioning system.
+Do not store or heat refrigerant containers above 52ÉC.
+Do not heat a refrigerant container with an open ¯ame; if container warming is required, place the
bottom of the container in a warm pail of water.
+Do not intentionally drop, puncture, or incinerate refrigerant containers.
+Keep refrigerant away from open ¯ames: poisonous gas will be produced if refrigerant burns.
+Refrigerant will displace oxygen, therefore be certain to work in well ventilated areas to prevent
suffocation.
+Do not introduce compressed air to any refrigerant container or refrigerant component.
Precautions for Refrigerant Connection
A new type refrigerant connection has been introduced to all refrigerant lines except the following location.
+Expansion valve to cooling unit
+A part of high-pressure line
FEATURES OF NEW TYPE REFRIGERANT CONNECTION
+The O-ring has been relocated. It has also been provided with a groove for proper installation. This elimi-
nates the chance of the O-ring being caught in, or damaged by, the mating part. The sealing direction of
the O-ring is now set vertically in relation to the contacting surface of the mating part to improve sealing
characteristics.
+The reaction force of the O-ring will not occur in the direction that causes the joint to pull out, thereby
facilitating piping connections.
CAUTION:
The new and former refrigerant connections use different O-ring con®gurations. Do not confuse
O-rings since they are not interchangeable. If a wrong O-ring is installed, refrigerant will leak at, or
around, the connection.
SHA815E
PRECAUTIONS AND PREPARATIONMANUAL AND AUTO
HA-2