
Symptom Matrix ChartNLEC0041SYSTEM Ð ENGINE CONTROL SYSTEMNLEC0041S01
SYMPTOM
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)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit11232 22 3 2EC-516
Fuel pressure regulator system334444444 4EC-44
Injector circuit11232 22 2EC-495
Evaporative emission system334444444 4EC-39
Air Positive crankcase ventilation sys-
tem334444444 41EC-42
Incorrect idle speed adjustment 3 31111 1EC-46
IACV-AAC valve circuit112332222 2 2EC-343
Ignition Incorrect ignition timing adjust-
ment33111 11 1EC-46
Ignition circuit11222 22 2EC-500
EGR
(where
fitted)EGR volume control valve circuit2233 3EC-319
EGR system212333223 3EC-310, 319,
393
Main power supply and ground circuit22333 33 23 2EC-146
Air conditioner circuit223333333 3 2HAsection
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG18DE
Symptom Matrix Chart
EC-124 

SYMPTOM
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)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Crankshaft position sensor (POS)
circuit22EC-295
Camshaft position sensor
(PHASE) circuit3 2 3 EC-302
Mass air flow sensor circuit11222 22 2EC-154
Heated oxygen sensor 1 (front)
circuit1232 22 2EC-184,
192
Engine coolant temperature sen-
sor circuit112323223 2EC-169,
171
Throttle position sensor circuit 1 222222 2EC-175
Incorrect throttle position sensor
adjustment31 11111 1EC-99
Vehicle speed sensor circuit 2 3 3 3 EC-338
Knock sensor circuit 2 3 EC-291
ECM 22333333333EC-358,
123
Start signal circuit 2EC-512
PNP switch circuit 3 3 3 3 3 EC-402
Power steering oil pressure
switch circuit2 3 3 EC-524
Electrical load signal circuit 3 3 EC-535
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG18DE
Symptom Matrix Chart (Cont'd)
EC-125 

SYSTEM Ð ENGINE MECHANICAL & OTHERNLEC0041S03
SYMPTOM
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)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank
5
5FE section
Fuel piping 5 5 5 5 5 5
Ð Vapor lock
Valve deposit
5 555 55 5
Poor fuel (Heavy weight gasoline,
Low octane)
Air Air duct
55555 5 Air cleaner
Air leakage from air duct
(Mass air flow sensor Ð throttle
body)
5555
Throttle body, Throttle wireFE section
Air leakage from intake manifold/
Collector/GasketÐ
Cranking Battery
111111 11
EL section Alternator circuit
Starter circuit 3
Flywheel/drive plate 6 EM section
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG18DE
Symptom Matrix Chart (Cont'd)
EC-126 

SYMPTOM
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)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Engine Cylinder head
55555 55 5
EM section Cylinder head gasket 4 3
Cylinder block
66666 66 64 Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Valve
mecha-
nismTiming chain
55555 55 5 EMsection Camshaft
Intake valve
3
Exhaust valve
Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5 FEsection
Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery
55555 55 5MA, EM and
LC sections
Oil level (Low)/Filthy oil
LC section Cooling Radiator/Hose/Radiator filler cap
55555 55 45 Thermostat 5
Water pump
Water gallery
Cooling fan 5 EC-373
Coolant level (low)/Contaminated
coolantMA section
1 - 6: The numbers refer to the order of inspection.
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONQG18DE
Symptom Matrix Chart (Cont'd)
EC-127 

DescriptionNLEC0522SYSTEM DESCRIPTIONNLEC0522S01
Sensor Input Signal to ECMECM func-
tionActuator
Throttle position sensor Throttle position
Swirl con-
trol valve
system
controlSwirl control valve control sole-
noid valve via swirl control
valve Ignition switch Start signal
Crankshaft position sensor (POS) Engine speed
Camshaft position sensor (PHASE) Engine speed and cylinder number
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
This system has a swirl control valve in the intake passage of each cylinder.
While idling and during low engine speed operation, the swirl control valve closes. Thus the velocity of the air
in the intake passage increases, promoting the vaporization of the fuel and producing a swirl in the combus-
tion chamber.
Because of this operation, this system tends to increase the burning speed of the gas mixture, improve fuel
consumption, and increase the stability in running conditions.
Also, except when idling and during low engine speed operation, this system opens the swirl control valve.
The solenoid valve controls swirl control valve's shut/open condition. This solenoid valve is operated by the
ECM.
OPERATIONNLEC0522S02
Engine coolant tempera-
tureThrottle position sensor
(Idle position)Engine speedSwirl control valve con-
trol solenoid valveSwirl control valve
15 - 40ÉC
(59 - 104ÉF)ON Ð
ON Closed
OFF Below 2,400 rpm*
Except above OFF Open
*: The value may vary according to accelerator pedal operation.
SEF081X
CONSULT-II Reference Value in Data Monitor
Mode
NLEC0523Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
SWRL CONT S/V+Engine speed: IdleEngine coolant temperature is
between 15ÉC (59ÉF) to 40ÉC
(104ÉF).ON
Engine coolant temperature is
above 40ÉC (104ÉF).OFF
DTC P1131 SWIRL CONTROL VALVE SOLENOID VALVE (CIRCUIT)
(WHERE FITTED)
QG18DE
Description
EC-366 

DescriptionNLEC1248SYSTEM DESCRIPTIONNLEC1248S01
Sensor Input Signal to ECMECM func-
tionActuator
Throttle position sensor Throttle position
Swirl con-
trol valve
system
controlSwirl control valve control sole-
noid valve via swirl control
valve Ignition switch Start signal
Crankshaft position sensor (POS) Engine speed
Camshaft position sensor (PHASE) Engine speed and cylinder number
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
This system has a swirl control valve in the intake passage of each cylinder.
While idling and during low engine speed operation, the swirl control valve closes. Thus the velocity of the air
in the intake passage increases, promoting the vaporization of the fuel and producing a swirl in the combus-
tion chamber.
Because of this operation, this system tends to increase the burning speed of the gas mixture, improve fuel
consumption, and increase the stability in running conditions.
Also, except when idling and during low engine speed operation, this system opens the swirl control valve.
The solenoid valve controls swirl control valve's shut/open condition. This solenoid valve is operated by the
ECM.
OPERATIONNLEC1248S02
Engine coolant tempera-
tureThrottle position sensor
(Idle position)Engine speedSwirl control valve con-
trol solenoid valveSwirl control valve
15 - 40ÉC
(59 - 104ÉF)ON Ð
ON Closed
OFF Below 2,400 rpm*
Except above OFF Open
*: The value may vary according to accelerator pedal operation.
SEF081X
CONSULT-II Reference Value in Data Monitor
Mode
NLEC1249Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
SWRL CONT S/V+Engine speed: IdleEngine coolant temperature is
between 15ÉC (59ÉF) to 40ÉC
(104ÉF).ON
Engine coolant temperature is
above 40ÉC (104ÉF).OFF
SWIRL CONTROL VALVE CONTROL SYSTEM
(WHERE FITTED)
QG18DE
Description
EC-481 

Symptom Matrix ChartNLEC1372SYSTEM Ð ENGINE CONTROL SYSTEMNLEC1372S01
SYMPTOM
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)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit11232 22 3 2EC-1032
Fuel pressure regulator system334444444 4EC-578
Injector circuit11232 22 2EC-1021
Evaporative emission system334444444 4EC-573
Air Positive crankcase ventilation sys-
tem334444444 41EC-576
Incorrect idle speed adjustment 3 31111 1EC-623
IACV-AAC valve circuit112332222 2 2EC-863, 995
Ignition Incorrect ignition timing adjust-
ment33111 11 1EC-623
Ignition circuit11222 22 2EC-900, 1004
EGR
(where
fitted)EGR volume control valve circuit2233 3EC-841
EGR system212333223 3EC-834, 841,
921
Main power supply and ground circuit22333 33 23 2EC-671
Air conditioner circuit223333333 3 2HAsection
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONSR20DE
Symptom Matrix Chart
EC-648 

SYMPTOM
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)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Crankshaft position sensor (OBD)
circuit22EC-819,
969
Camshaft position sensor circuit 3 2 3 EC-825
Mass air flow sensor circuit11222 22 2EC-679
Heated oxygen sensor 1 (front)
circuit1232 22 2EC-709,
944
Engine coolant temperature sen-
sor circuit112323223 2EC-694
Throttle position sensor circuit 1 222222 2EC-700
Incorrect throttle position sensor
adjustment31 11111 1EC-623
Vehicle speed sensor circuit 2 3 3 3 EC-858
Knock sensor circuit 2 3 EC-815
ECM 22333333333EC-880,
647
Start signal circuit 2EC-1027
PNP switch circuit 3 3 3 3 3 EC-931
Power steering oil pressure
switch circuit2 3 3 EC-1039
Electrical load signal circuit 3 3 EC-1050
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTIONSR20DE
Symptom Matrix Chart (Cont'd)
EC-649