ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-57
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EXPLANATION FOR DRIVING PATTERNS EXCEPT FOR “MISFIRE
●The A counter will be cleared when the malfunction is detected regardless of (1) - (4).
●The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.
●The DTC will not be displayed after the A counter reaches 40.
Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.
●The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
●The B counter will be counted up when driving pattern B is satisfied without any malfunctions.
●The MI will go off when the B counter reaches 3 (*2 in “OBD SYSTEM OPERATION CHART”).
AEC574
EC-58
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
PFP:00004
Trouble Diagnosis IntroductionEBS00K3L
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose a incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the “Work Flow” on EC-59
.
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple on EC-62
should be used.
Start your diagnosis by looking for “conventional” malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
SEF234G
TROUBLE DIAGNOSIS
EC-61
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DIAGNOSTIC WORKSHEET
Description
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about a incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MI to come on steady or blink and
DTC to be detected. Examples:
●Vehicle ran out of fuel, which caused the engine to misfire.
●Fuel filler cap was left off or incorrectly screwed on, allowing fuel
to evaporate into the atmosphere.
SEF907L
TROUBLE DIAGNOSIS
EC-63
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Fail-safe ChartEBS00K3N
●When the DTC listed below is detected, the ECM enters fail-safe mode and the MI lights up.
Priority Detected items (DTC)
1
●U1000 U1001 CAN communication line
●P0102 P0103 Mass air flow sensor
●P0112 P0113 Intake air temperature sensor
●P0117 P0118 Engine coolant temperature sensor
●P0221 P0222 P0223 P1223 P1224 P1225 P1226 P1229 Throttle position sensor
●P0226 P0227 P0228 P1227 P1228 Accelerator pedal position sensor
●P0327 P0328 Knock sensor
●P0335 Crankshaft position sensor (POS)
●P0340 Camshaft position sensor (PHASE)
●P0500 Vehicle speed sensor
●P0705 Park/Neutral position (PNP) switch
●P0605 ECM
●P1610-P1615 NATS
●P1706 Park/Neutral position (PNP) switch
2
●P0031 P0032 Heated oxygen sensor 1 heater
●P0037 P0038 Heated oxygen sensor 2 heater
●P0132 P0133 P0134 P1143 P1144 Heated oxygen sensor 1
●P0138 P0139 P1146 P1147 Heated oxygen sensor 2
●P0550 Power steering pressure sensor
●P0710-P0725 P0740-P0755 P1705 P1760 A/T related sensors and solenoid valves
●P1065 ECM power supply
●P 1111 I n ta k e v a l v e t i m i n g c o n t r o l s o l e n o i d v a l v e
●P1122 Electric throttle control function
●P1124 P1126 P1128 Electric throttle control actuator
●P1805 Brake switch
3
●P0011 Intake valve timing control
●P0171 P0172 Fuel injection system function
●P0300 - P0304 Misfire
●P0420 Three way catalyst function
●P0444 EVAP canister purge volume control solenoid valve
●P0731-P0734 A/T function
●P1121 Electric throttle control actuator
●P1217 Engine over temperature (OVERHEAT)
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
EC-64
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
●When there is an open circuit on MI circuit, the ECM cannot warn the driver by lighting MI up when there
is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MI circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MI circuit and demands the driver to
repair the trouble.
P0117
P0118Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning
ignition switch “ON” or “START”.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided (CONSULT-
II display)
Just as ignition switch is turned
ON or Start40°C (104°F)
More than approx. 4 minutes after
ignition ON or Start80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cool-
ing fan operates while engine is running.
P0221
P0222
P0223
P1223
P1224Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening
in order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the nor-
mal condition.
So, the acceleration will be poor.
P0226
P0227
P0228
P1227
P1228Accelerator pedal position
sensorThe ECM controls the electric throttle control actuator in regulating the throttle opening
in order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the nor-
mal condition.
So, the acceleration will be poor.
P1121 Electric throttle control actu-
ator
(ECM detect the throttle
valve is stuck open.)While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops,
the engine stalls.
The engine can restart in “N” or “P” position, and engine speed will not exceed 1,000
rpm or more.
P1122 Electric throttle control func-
tionECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1124
P1126Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1128
Throttle control motorECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring
P1229 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring. DTC No. Detected items Engine operating condition in fail-safe mode
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
EC-70
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
Symptom Matrix Chart
EBS00K3P
SYSTEM — BASIC ENGINE CONTROL SYSTEM
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 circuit 11232 22 3 2EC-381
Fuel pressure regulator system334444444 4EC-34
Injector circuit 11232 22 2EC-375
Evaporative emission system 334444444 4EC-251,
EC-399
Air Positive crankcase ventilation sys-
tem334444444 41EC-402
Incorrect idle speed adjustment 33 1111 1EC-65
Electric throttle control actuator 112332222 2 2EC-276
,
EC-278
,
EC-285
,
EC-291
IgnitionIncorrect ignition timing adjustment33111 11 1EC-65
Ignition circuit 11222 22 2EC-365
Main power supply and ground circuit 22333 33 23EC-110
Mass air flow sensor circuit 11222 22 2EC-134
Engine coolant temperature sensor circuit 11222322312EC-144
Throttle position sensor circuit 12 22222 2EC-199
,
EC-205
,
EC-335
,
EC-341
,
EC-343
,
EC-352
Accelerator pedal position sensor circuit3212 2EC-211
,
EC-218
,
EC-345
Heated oxygen sensor 1 circuit 1232 22 2EC-149
,
EC-155
,
EC-165
,
EC-296
,
EC-302
Knock sensor circuit 2 2 3EC-230
Crankshaft position sensor (POS) circuit 2 2EC-234
Camshaft position sensor (PHASE) circuit 2 2EC-240
Vehicle speed signal circuit 2 3 3 3EC-257
TROUBLE DIAGNOSIS
EC-71
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1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Power steering pressure sensor circuit 2 3 3 3 3EC-260
ECM 22333333333EC-265,
EC-268
Intake valve timing control solenoid valve cir-
cuit332 13223 3EC-272
PNP switch circuit 3 33333 3EC-356
Refrigerant pressure sensor circuit 2 3 3 3 3 4EC-387
Electrical load signal circuit 3 3 3 3EC-392
Air conditioner circuit223333333 3 2AT C - 2 9
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
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-4
Fuel piping 5 5 5 5 5 5 FE-4
Vapor lock—
Valve deposit
555555 5—
Poor fuel (Heavy weight gaso-
line, Low octane)—
EC-72
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
Air Air duct
55555 5EM-14
Air cleanerEM-14
Air leakage from air duct
(Mass air flow sensor —electric
throttle control actuator)
5555EM-14
Electric throttle control actuatorEM-16
Air leakage from intake manifold/
Collector/GasketEM-16
Cranking Battery
111111 11SC-3
Alternator circuitSC-27
Starter circuit 3 SC-13
Signal plate/Flywheel/Drive plate 6EM-70
PNP switch
4AT- 11 6,
MT-21
Engine Cylinder head
55555 55 5EM-57
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-70
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nismTimin g c hain
55555 55 5EM-47
CamshaftEM-32
Intake valve timing controlEM-47
Intake valve
3EM-57
Exhaust valve
Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5EM-19
, FE-
26
Three way catalyst
Lubrica-
tionOil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery
55555 55 52EM-22
, LC-
5, LC-9,
LC-4
Oil level (Low)/Filthy oilLC-8 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