
SYSTEM
Ð Engine mechanical & otherSYMPTOM
Reference page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
OVERCOOLS
OVERCHARGING
Warranty Symptom Code AA AB AC AD AE AF AG AH AJ AK AL AM HA 1P 1X
Fuel Fuel tank
ll
Ð Fuel piping
lljjljj j
Vapor lockj
Valve depositjjjjj jj j
Poor fuel (Heavy weight gasoline, Low
octane)jjjjj jj j
Air Air ductjjjjj j
Air cleanerj
llljj
Air leakage from air duct
(Mass air flow sensor Ð throttle body)jjjjjjjjj j
Throttle body, Throttle wirej
lljlljj jFE section
Air leakage from intake manifold/
Collector/Gasketj
ljjjjljjlÐ
Cranking Batteryjjjjjj jjj
EL section Alternator circuitjjjjjj jjj
Starter circuit
l
FlywheellÐ
Engine Cylinder head
ljljjljj
Ð Cylinder head gasketjjjjj
ljljj
Cylinder blockjjjj
ljj jj
Pistonjjjjj j
ljl
Piston ringjjjjlljjl
Connecting rodljjjj jj j
Bearing
lljljjlj
Crankshaftjjjjj jj j
Valve
mechanismTiming chain
ljljljj j
Camshaft
ljjjj jj j
Intake valvej
lljjljjj
Exhaust valve
ljljlljjl
Exhaust Exhaust manifold/Tube/Muffler/Gasketjllll ljl
Three way catalystjljjljj j
Lubrication Oil pan/Oil strainer/Oil pump/Oil filter/Oil
gallery
ljjlljj jl
Oil level (Low)/Filthy oiljjjjj jj jj
Cooling Radiator/Hose/Radiator filler capjjjjj jj
lj
Thermostatjjjjjj
ljjljj
Water pump
ljjjj jjlj
Water galleryjjjjj jj jj
Cooling fanjjjj
ljljjljj
Coolant level (low)/Contaminated coolantjjjjj jj jj
l; High Possibility Item
j; Low Possibility Item
TROUBLE DIAGNOSIS Ð General DescriptionKA
Symptom Matrix Chart (Cont'd)
EC-63

Overheat
ON BOARD DIAGNOSIS LOGIC
If the cooling fan or another component in the cooling system malfunctions, the engine coolant temperature
will rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
Diagnostic trouble
code No.Malfunction is detected when ...Check Items
(Possible Cause)
28
lEngine coolant temperature reaches an abnormally
high temperature.lCooling fan
lRadiator hose
lRadiator
lRadiator cap
lWater pump
lThermostat
For more information, refer to ``MAIN 12
CAUSES OF OVERHEATING'', EC-108.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in MA sec-
tion (``Changing Engine Coolant'', ``ENGINE MAINTENANCE''). Also, replace the engine oil.
lFill radiator with coolant up to specified level with a filling speed of 2 liters per minute like pour-
ing coolant by kettle. Be sure to use coolant with the proper mixture ratio. Refer to MA section
(``Anti-freeze Coolant Mixture Ratio'', ``RECOMMENDED FLUIDS AND LUBRICANTS'').
lAfter refilling coolant, run engine to ensure that no water-flow noise is emitted.
OVERALL FUNCTION CHECK
WARNING:
Never remove the radiator cap when the engine is hot. Seri-
ous burns could be caused by high pressure fluid escaping
from the radiator.
Wrap a thick cloth around cap. Carefully remove the cap by
turning it a quarter turn to allow built-up pressure to escape.
Then turn the cap all the way off.
1. Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is
below the proper range, skip the following step and go to
``DIAGNOSTIC PROCEDURE'' on next page.
2. Confirm whether customer filled the coolant or not. If cus-
tomer filled the coolant, go to ``DIAGNOSTIC PROCEDURE''
on next page.
AEC640
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)KA
EC-106

DIAGNOSTIC PROCEDURE
INSPECTION START
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 specified pressure may
cause radiator damage.
OK
cNG
Check the following for leak.
lHoselRadiatorlWater 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:
76.5ÉC (170ÉF) [standard]
Valve lift:
More than 10 mm/90ÉC
(0.39 in/194ÉF)
3. Check if valve is closed at 5ÉC (9ÉF) below
valve opening temperature.
For details, refer to LC section (``Thermostat'').
OK
cNG
Replace thermostat.
Check engine coolant temperature sensor.
Refer to ``COMPONENT INSPECTION'',
EC-98.
OK
cNG
Replace engine coolant tem-
perature 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 instru-
ment 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
SLC755AA
SLC343
.
.
.
.
.
.
TROUBLE DIAGNOSIS FOR ``OVER HEAT'' (DTC 28)KA
Overheat (Cont'd)
EC-107

MAIN 12 CAUSES OF OVERHEATING
Engine Step Inspection item Equipment Standard Reference page
OFF 1
lBlocked radiator
lBlocked condenser
lBlocked radiator grille
lBlocked bumper
lVisual No blocking Ð
2
lCoolant mixturelCoolant tester 50 - 50% coolant mixture See ``RECOMMENDED
FLUIDS AND LUBRI-
CANTS'' in MA section.
3
lCoolant levellVisual Coolant up to MAX level
in reservoir tank and
radiator filler neckSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
4
lRadiator caplPressure tester 78 - 98 kPa
(0.78 - 0.98 bar, 0.8 - 1.0
kg/cm
2, 11 - 14 psi)
59 - 98 kPa (0.59 - 0.98
bar, 0.6 - 1.0 kg/cm
2,
9 - 14 psi) (Limit)See ``System Check'',
``ENGINE COOLING
SYSTEM'' in LC section.
ON*2 5
lCoolant leakslVisual No leaks See ``System Check'',
``ENGINE COOLING
SYSTEM'' in LC section.
ON*2 6
lThermostatlTouch the upper and
lower radiator hosesBoth hoses should be hot. See ``Thermostat'' and
``Radiator'', ``ENGINE
COOLING SYSTEM'' in
LC section.
ON*1 7
lCooling fanlVisual Operating See ``Cooling Fan'',
``ENGINE COOLING
SYSTEM'' in LC section.
OFF 8
lCombustion gas leaklColor checker chemical
tester 4 gas analyzerNegative Ð
ON*3 9
lCoolant temperature
gaugelVisual Gauge less than 3/4
when drivingÐ
lCoolant overflow to res-
ervoir tanklVisual No overflow during driving
and idlingSee ``Changing Engine
Coolant'', ``ENGINE
MAINTENANCE'' in MA
section.
OFF*4 10
lCoolant return from res-
ervoir tank to radiatorlVisual Should be initial level in
reservoir tankSee ``ENGINE MAINTE-
NANCE'' in MA section.
OFF 11
lCylinder headlStraight gauge feeler
gauge0.1 mm (0.004 in) Maxi-
mum distortion (warping)See ``Inspection'', ``CYL-
INDER HEAD'' in EM
section.
12
lCylinder block and pis-
tonslVisual No scuffing on cylinder
walls or pistonSee ``Inspection'', ``CYL-
INDER BLOCK'' in EM
section.
*1: Engine running at idle.
*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)KA
Overheat (Cont'd)
EC-108

lBefore jacking up the vehicle, apply wheel chocks or other
tire blocks to the wheels to prevent the vehicle from moving.
After jacking up the vehicle, support the vehicle weight with
safety stands at the points designated for proper lifting before
working on the vehicle.
These operations should be done on a level surface.
lWhen removing a heavy component such as the engine or
transaxle/transmission, be careful not to lose your balance
and drop them. Also, do not allow them to strike adjacent
parts, especially the brake tubes and master cylinder.
lBefore starting repairs which do not require battery power:
Turn off ignition switch.
Disconnect the negative battery terminal.
lTo prevent serious burns:
Avoid contact with hot metal parts.
Do not remove the radiator cap when the engine is hot.
lBefore servicing the vehicle:
Protect fenders, upholstery and carpeting with appropriate
covers.
Take caution that keys, buckles or buttons do not scratch
paint.
lClean all disassembled parts in the designated liquid or sol-
vent prior to inspection or assembly.
lReplace oil seals, gaskets, packings, O-rings, locking
washers, cotter pins, self-locking nuts, etc. with new ones.
lReplace inner and outer races of tapered roller bearings and
needle bearings as a set.
lArrange the disassembled parts in accordance with their
assembled locations and sequence.
lDo not touch the terminals of electrical components which
use microcomputers (such as ECMs).
Static electricity may damage internal electronic compo-
nents.
SGI231
SEF289H
SGI233
SGI234
PRECAUTIONS
General Precautions (Cont'd)
GI-3

PRELIMINARY CHECK 3
Insufficient heating
DOES AIR FLOW FROM FOOT AREA?
Condition:
lVehicle at operating temperature.
lIgnition switch and fan switch are ON.
lMode control lever is in FOOT position and tem-
perature control lever is in full hot position.
Yes
cNoCHECK BLOWER MOTOR
OPERATION.
Go toDiagnostic Procedure
1, HA-37.
Check the following:
lEngine coolant level. Refer to MA section.
lHoses for leaks or kinks.
lRadiator cap. Refer to LC section (``ENGINE
COOLING SYSTEM'').
lAir in cooling system.
OK
cNG
Repair/replace as necessary.
CHECK WATER COCK OPERATION.
Except for RHD models
Warm up engine before checking.
Refer to ``Control Linkage Adjustment'', HA-46.
OK
cNG
Adjust or replace water cock.
CHECK TEMPERATURE CONTROL CABLE.
Refer to ``Control Linkage Adjustment'', HA-47.
OK
cNG
Adjust temperature control
cable.
VISUALLY INSPECT AIR MIX DOOR.
Access by removing instrument panel.
OK
cNG
Replace air mix door.
CHECK BY FEEL HEATER INLET AND OUTLET
HOSES.
Both hoses
coldBoth hoses
warm
CHECK THERMOSTAT
INSTALLATION.
OKCHECK HEATER HOSES FOR
PROPER INSTALLATION.OK
Replace thermostat. Refer
to LC section (``Thermostat'',
``ENGINE COOLING SYS-
TEM'').
Back flush heater core, drain and refill coolant.
Retest.
Hot inlet
Warm outletBoth hoses
warm
System OK
Replace heater
core.
.
.
.
.
.
..
..
..
TROUBLE DIAGNOSES
Preliminary Check (Cont'd)
HA-23

Special Service Tools*: Special tool or commercial equivalent
Tool number
Tool nameDescriptionEngine application
KA TD
ST25051001*
Oil pressure gauge
NT558
Measuring oil pres-
sure
Maximum measur-
ing range: 2,452
kPa (24.5 bar, 25
kg/cm
2, 356 psi)XX
ST25052000*
Hose
NT559
Adapting oil pres-
sure gauge
to cylinder block
XX
EG17650301
Radiator cap tester
adapter
NT564
Adapting radiator
cap tester
to radiator filler
neck
XX
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
KV99103510
Radiator plate pliers A
NT224
Installing radiator
upper and lower
tanks
XX
KV99103520
Radiator plate pliers B
NT225
Removing radiator
upper and lower
tanks
XX
WS39930000
Tube presser
NT052
Pressing the tube
of liquid gasket
XX
KV10105901
Oil filter cap wrench
NT689
Removing oil filter
XÐ
KV10106001
Oil filter wrench
NT690
Replacing oil filter
ÐX
PRECAUTIONS AND PREPARATION
LC-2

Cooling Circuit
System Check
WARNING:
Never remove the radiator cap when the engine is hot. Seri-
ous burns could occur from high pressure coolant escaping
from the radiator.
Wrap a thick cloth around the cap. Slowly turn it a quarter
turn to allow built-up pressure to escape. Carefully remove
the cap by turning it all the way.
CHECKING COOLING SYSTEM HOSES
Check hoses for the following:
lImproper attachment
lLeaks
lCracks
lDamage
lChafing
lDeterioration
SLC138B
ENGINE COOLING SYSTEMKA
LC-6