Diagnostic Trouble Code Clearance 6-14. . . . .
Diagnostic Trouble Code Table 6-15. . . . . . . . .
Fail-safe Table 6-18. . . . . . . . . . . . . . . . . . . . . . .
Visual Inspection 6-19. . . . . . . . . . . . . . . . . . . . .
Engine Basic Inspection 6-20. . . . . . . . . . . . . . .
Engine Diagnosis Table 6-22. . . . . . . . . . . . . . .
Scan Tool Data 6-29. . . . . . . . . . . . . . . . . . . . . . .
Scan Tool Data Definitions 6-31. . . . . . . . . . . . .
Inspection of ECM (PCM) and Its Circuits 6-33
Voltage Check 6-33. . . . . . . . . . . . . . . . . . . . .
Resistance Check 6-37. . . . . . . . . . . . . . . . . .
Component Location 6-38. . . . . . . . . . . . . . . . . .
Table A-1 MIL Circuit Check
(Lamp does not come on) 6-39. . . . . . . . . . . .
Table A-2 MIL Circuit Check
(Lamp remains ON) 6-40. . . . . . . . . . . . . . . . . .
Table A-3 ECM (PCM) Power and Ground
Circuit Check 6-42. . . . . . . . . . . . . . . . . . . . . . .
DTC P0105 MAP Circuit Malfunction 6-44. . . .
DTC P0110 IAT Circuit Malfunction 6-46. . . . .
DTC P0115 ECT Circuit Malfunction 6-48. . . .
DTC P0120 Throttle Position Circuit
Malfunction 6-50. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0121 Throttle Position Circuit
Range / Performance Problem 6-52. . . . . . . . .
DTC P0130 HO2S Circuit Malfunction
(Sensor-1) 6-54. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0133 HO2S Circuit Slow
Response (Sensor-1) 6-56. . . . . . . . . . . . . . . .
DTC P0135 HO2S Heater Circuit
Malfunction (Sensor-1) 6-57. . . . . . . . . . . . . . .
DTC P0136 HO2S Circuit Malfunction
(Sensor-2) 6-59. . . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0141 HO2S Heater Circuit
Malfunction (Sensor-2) 6-62. . . . . . . . . . . . . . .
DTC P0171 Fuel System Too Lean 6-64. . . . .
DTC P0172 Fuel System Too Rich 6-64. . . . . .
DTC P0300 Random Misfire Detected 6-68. . .
DTC P0301 Cylinder 1 Misfire Detected 6-68. DTC P0302 Cylinder 2 Misfire Detected 6- 68.
DTC P0303 Cylinder 3 Misfire Detected 6- 68.
DTC P0335 CKP Sensor Circuit
Malfunction 6- 72. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0340 CMP Sensor Circuit
Malfunction 6- 74. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0420 Catalyst System Efficiency
Below Threshold 6- 76. . . . . . . . . . . . . . . . . . . .
DTC P0443 Purge Control Valve Circuit
Malfunction 6- 79. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0480 Radiator Fan Control
System Malfunction 6- 80. . . . . . . . . . . . . . . . . .
DTC P0500 Vehicle Speed Sensor
Malfunction (M / T) 6- 82. . . . . . . . . . . . . . . . . . .
DTC P0500 Vehicle Speed Sensor
Malfunction (A / T) 6- 84. . . . . . . . . . . . . . . . . . .
DTC P0505 Idle Control System
Malfunction 6- 86. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P0510 Closed Throttle Position
Switch Malfunction 6- 88. . . . . . . . . . . . . . . . . .
DTC P0601 Internal Control Module
Memory Check Sum Error 6- 89. . . . . . . . . . . .
DTC P1250 EFE Heater Circuit
Malfunction 6- 90. . . . . . . . . . . . . . . . . . . . . . . . .
DTC P1450 Barometric Pressure
Sensor Low / High Input 6- 92. . . . . . . . . . . . . .
DTC P1451 Barometric Pressure Sensor
Performance Problem 6- 92. . . . . . . . . . . . . . . .
DTC P1500 Engine Starter Signal
Circuit Malfunction 6- 93. . . . . . . . . . . . . . . . . . .
DTC P1510 ECM (PCM) Back-up Power
Supply Malfunction 6- 94. . . . . . . . . . . . . . . . . .
Table B-1 Fuel Injector Circuit Check 6- 96. . . .
Table B-2 Fuel Pump and Its Circuit
Check 6- 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table B-3 Fuel Pressure Check 6-100. . . . . . . . .
Table B-4 A / C Signal Circuits Check 6-102. . . .
Table B-5 Power Steering Pressure
Switch Signal Circuit Check 6-103. . . . . . . . . . .
SPECIAL TOOL6-104 . . . . . . . . . . . . . . . . . . . . . . .
6-2 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
1. No.1 cylinder
2. No.2 cylinder
3. No.3 cylinder
123
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-3
GENERAL INFORMATION
STATEMENT ON CLEANLINESS AND CARE
An automobile engine is a combination of many machined, honed,
polished and lapped surfaces with tolerances that are measured in
the thousands of an millimeter (ten thousands of an inch).
Accordingly, when any internal engine parts are serviced, care and
cleanliness are important.
Throughout this section, it should be understood that proper clean-
ing and protection of machined surfaces and friction areas is part
of the repair procedure. This is considered standard shop practice
even if not specifically stated.
A liberal coating of engine oil should be applied to friction areas
during assembly to protect and lubricate the surfaces on initial op-
eration.
Whenever valve train components, pistons, piston rings, con-
necting rods, rod bearings, and crankshaft journal bearings are
removed for service, they should be retained in order.
At the time of installation, they should be installed in the same
locations and with the same mating surfaces as when removed.
Battery cables should be disconnected before any major work is
performed on the engine.
Failure to disconnect cables may result in damage to wire har-
ness or other electrical parts.
Throughout this manual, the four cylinders of the engine are iden-
tified by numbers; No.1 (1), No.2 (2) and No.3 (3) counted from
crankshaft pulley side to flywheel side.
GENERAL INFORMATION ON ENGINE SERVICE
THE FOLLOWING INFORMATION ON ENGINE SERVICE
SHOULD BE NOTED CAREFULLY, AS IT IS IMPORTANT IN PRE-
VENTING DAMAGE, AND IN CONTRIBUTING TO RELIABLE EN-
GINE PERFORMANCE.
When raising or supporting engine for any reason, do not use a
jack under oil pan. Due to small clearance between oil pan and
oil pump strainer, jacking against oil pan may cause it to be bent
against strainer resulting in damaged oil pick-up unit.
It should be kept in mind, while working on engine, that 12-volt
electrical system is capable of violent and damaging short cir-
cuits.
When performing any work where electrical terminals can be
grounded, ground cable of the battery should be disconnected at
battery.
Any time the air cleaner, throttle body or intake manifold is re-
moved, the intake opening should be covered. This will protect
against accidental entrance of foreign material which could follow
intake passage into cylinder and cause extensive damage when
engine is started.
6-16 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
DTC
NO.DETECTING ITEMDETECTING CONDITION
(DTC will set when detecting:)MIL
P0335Crankshaft position sensor
circuit malfunctionNo signal during engine running1 driving cycle
P0340Camshaft position sensor
circuit malfunctionNo signal for 2 sec. during engine cranking1 driving cycle
P0420Catalyst system efficiency
below threshold
Output waveforms of HO2S-1 and HO2S-2
are similar.
(Time from output voltage change of HO2S-1
to that of HO2S-2 is shorter than
specification.)
2 driving cycles
P0443EVAP Purge control valve
circuit malfunctionPurge control valve circuit is open or shorted
to ground2 driving cycles
P0480Radiator fan control circuit
malfunctionRadiator cooling fan relay terminal voltage is
low when cooling temp. is lower than
specification
2 driving cycles
P0500Vehicle speed sensor
malfunctionNo signal while running in “D” range or during
fuel cut at decelerating2 driving cycles
P0505Idle control system malfunction
Throttle opening change is small as compared
with electrically live time. Throttle valve opening
is not within its target range with CTP switch ON
or drive voltage exists though ECM (PCM) is not
outputting ISC drive command.
1 driving cycle
P0510Closed throttle position switch
malfunctionSwitch does not change from ON to OFF
(or from OFF to ON) even when vehicle speed
reaches over (or below) specification.
2 driving cycle
P1250Early Fuel Evaporation Heater
Circuit MalfunctionHeater monitor terminal voltage is higher than
specified value when EFE OFF or it is lower
than specified value when EFE ON.
2 driving cycles
P1450Barometric pressure sensor
circuit malfunctionBarometric pressure is lower or higher than
specification. (or sensor malfunction)1 driving cycle
P1451Barometric pressure sensor
performance problem
Difference between manifold absolute
pressure (MAP sensor value) and
barometric pressure (barometric pressure
sensor value) is larger than specification
during cranking.
2 driving cycles
P1500Starter signal circuit
malfunctionStarter signal is not inputted from engine
cranking till its start and after or it is always
inputted
2 driving cycles
P1510ECM (PCM) backup power
source malfunctionNo backup power after starting engine1 driving cycle
6-22 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
ENGINE DIAGNOSIS TABLE
Perform troubleshooting referring to following table when ECM (PCM) has detected no DTC and no abnormality
has been found in visual inspection and engine basic inspection previously.
Condition
Possible CauseReferring Item
Hard Starting
(Engine cranks OK)Ignition system out of order
Faulty spark plug
Leaky high-tension cord
Loose connection or disconnection of high-
tension cords or lead wires
Faulty ignition coil
Fuel system out of order
Dirty or clogged fuel hose or pipe
Malfunctioning fuel pump
Air inhaling from intake manifold gasket or
throttle body gasket
Fuel injector resistor malfunction
Engine and emission control system out of
order
Faulty idle control system
Faulty ECT sensor or MAP sensor
Faulty ECM (PCM)
Low compression
Poor spark plug tightening or faulty gasket
Compression leak from valve seat
Sticky valve stem
Weak or damaged valve springs
Compression leak at cylinder head gasket
Sticking or damaged piston ring
Worn piston, ring or cylinder
Others
Malfunctioning PCV valve
Spark plugs in Section 6F
High-tension cords in Section 6F
High-tension cords in Section 6F
Ignition coil in Section 6F
Diagnostic Flow Table B-3
Diagnostic Flow Table B-3
Fuel injector resistor in Section 6E1
Diagnostic Flow Table P0505
ECT sensor or MAP sensor in
Section 6E1
Compression check in Section
6A
Spark plugs in Section 6F
Valves inspection in Section 6A
Valves inspection in Section 6A
Valve springs inspection in
Section 6A
Cylinder head inspection in
Section 6A
Cylinders, pistons and piston rings
inspection in Section 6A
Cylinders, pistons and piston rings
inspection in Section 6A
PCV system in Section 6E1
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-23
ConditionPossible CauseReferring Item
Low oil pressureImproper oil viscosity
Malfunctioning oil pressure switch
Clogged oil strainer
Functional deterioration of oil pump
Worn oil pump relief valve
Excessive clearance in various sliding partsEngine oil and oil filter change in
Section 0B
Oil pressure switch inspection in
Section 8
Oil pan and oil pump strainer
cleaning in Section 6A
Oil pump in Section 6A
Oil pump in Section 6A
Engine noise
Note: Before
checking mechanical
noise, make sure
that:
Specified spark
plug in used.
Specified fuel is
used.Valve noise
Improper valve lash
Worn valve stem and guide
Weak or broken valve spring
Warped or bent valve
Piston, ring and cylinder noise
Worn piston, ring and cylinder bore
Connecting rod noise
Worn rod bearing
Worn crank pin
Loose connecting rod nuts
Low oil pressure
Crankshaft noise
Low oil pressure
Worn bearing
Worn crankshaft journal
Loose bearing cap bolts
Excessive crankshaft thrust play
Valve lash in Section 6A
Valves inspection in Section 6A
Valve springs inspection in
Section 6A
Valves inspection in Section 6A
Pistons and cylinders inspection
in Section 6A
Crank pin and connecting rod
bearing inspection in Section 6A
Crank pin and connecting rod
bearing inspection in Section 6A
Connecting rod installation in
Section 6A
Previously outlined
Previously outlined
Crankshaft and bearing
inspection in Section 6A
Crankshaft and bearing
inspection in Section 6A
Crankshaft inspection in
Section 6A
Crankshaft thrust play inspection
in Section 6A
6-24 ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10)
ConditionPossible CauseReferring Item
OverheatingInoperative thermostat
Poor water pump performance
Clogged or leaky radiator
Improper engine oil grade
Clogged oil filter or oil strainer
Poor oil pump performance
Faulty radiator fan control system
Dragging brakes
Slipping clutch
Blown cylinder head gasketThermostat in Section 6B
Water pump in Section 6B
Radiator in Section 6B
Engine oil and oil filter change in
Section 0B
Oil pressure check in Section 6A
Oil pressure check in Section 6A
Radiator fan control system in
Section 6E1
Trouble diagnosis in Section 5
Trouble diagnosis in Section 7C
Cylinder head in Section 6A
Poor gasoline
mileageIgnition system out of order
Leaks or loose connection of high-tension cord
Faulty spark plug (improper gap, heavy deposits
and burned electrodes, etc.)
Engine and emission control system out of
order
High idle speed
Poor performance of TP sensor, ECT sensor or
MAP sensor
Faulty fuel injector
Faulty fuel injector resistor
Faulty ECM (PCM)
Low compression
Others
Poor valve seating
Dragging brakes
Slipping clutch
Thermostat out of order
Improper tire pressure
High-tension cords in Section 6F
Spark plugs in Section 6F
Refer to item “Improper engine
idle speed” previously outlined
TP sensor, ECT sensor or MAP
sensor in Section 6E1
Diagnostic Flow Table B-1
Fuel injector resistor in Section 6E1
Previously outlined
Valves inspection in Section 6A
Trouble diagnosis in Section 5
Trouble diagnosis in Section 7C
Thermostat in Section 6B
Refer to Section 3F
Excessive engine
oil consumptionOil leakage
Blown cylinder head gasket
Leaky camshaft oil seals
Oil entering combustion chamber
Sticky piston ring
Worn piston and cylinder
Worn piston ring groove and ring
Improper location of piston ring gap
Worn or damaged valve stem seal
Worn valve stem
Cylinder head in Section 6A
Camshaft in Section 6A
Piston cleaning in Section 6A
Pistons and cylinders inspection
in Section 6A
Pistons inspection in Section 6A
Pistons assembly in Section 6A
Valves removal and installation in
Section 6A
Valves inspection in Section 6A
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-27
ConditionPossible CauseReferring Item
Improper engine
idling or engine
fails to idleIgnition system out of order
Faulty spark plug
Leaky or disconnected high-tension cord
Faulty ignition coil with ignitor
Fuel system out of order
Fuel pressure out of specification
Leaky manifold, throttle body, or cylinder head
gasket
Engine and emission control system out of
order
Faulty idle control system
Faulty evaporative emission control system
Faulty fuel injector
Faulty fuel injector resistor
Poor performance of ECT sensor, TP sensor or
MAP sensor
Faulty ECM (PCM)
Engine overheating
Low compression
Others
Loose connection or disconnection of vacuum
hoses
Malfunctioning PCV valve
Spark plugs in Section 6F
High-tension cords in Section 6F
Ignition coil in Section 6F
Diagnostic Flow Table B-3 in
Section 6
Diagnostic Flow Table P0505
EVAP control system in Section
6E
Diagnostic Flow Table B-1
Fuel injector resistor in Section 6E1
ECT sensor, TP sensor or MAP
sensor in Section 6E1
Refer to “Overheating” section
Previously outlined
PCV system in Section 6E1
ENGINE GENERAL INFORMATION AND DIAGNOSIS (TBI FOR G10) 6-29
Ambient temp.
SCAN TOOL DATA
As the data values given below are standard values estimated on the basis of values obtained from the normally
operating vehicles by using a scan tool, use them as reference values. Even when the vehicle is in good condition,
there may be cases where the checked value does not fall within each specified data range. Therefore, judgment
as abnormal should not be made by checking with these data alone.
Also, conditions in the below table that can be checked by the scan tool are those detected by ECM (PCM) and
output from ECM (PCM) as commands and there may be cases where the engine or actuator is not operating (in
the condition) as indicated by the scan tool. Be sure to use the timing light to check the ignition timing.
NOTE:
With the generic scan tool, only star () marked data in the table below can be read.
When checking the data with the engine running at idle or racing, be sure to shift M / T gear to the neutral
gear position and A / T gear to the “Park” position and pull the parking brake fully. Also, if nothing or “no
load” is indicated, turn OFF A / C, all electric loads, P / S and all the other necessary switches.
SCAN TOOL DATAVEHICLE CONDITIONNORMAL CONDITION /
REFERENCE VALUES
FUEL SYSTEM B1 (FUEL
SYSTEM STATUS)At specified idle speed after warming upCLOSED (closed loop)
CALC LOAD
(CALCULATED LOADAt specified idle speed with no load after
warming up3 – 5%(
VALUE)At 2500 r / min with no load after warming up10 – 18%
COOLANT TEMP.
(ENGINE COOLANT
TEMP.)
At specified idle speed after warming up85 – 95C, 185 – 203F
SHORT FT BI (SHORT
TERM FUEL TRIM)At specified idle speed after warming up–20 – +20%
LONG FT BI (LONG
TERM FUEL TRIM)At specified idle speed after warming up–15 – +15%
MAP (INTAKE
MANIFOLD ABSOLUTE
PRESSURE)At specified idle speed with no load after
warming up29 – 48 kPa,
220 – 360 mmHg
ENGINE SPEEDAt idling with no load after warming upDesired idle speed
± 50 r / min
VEHICLE SPEEDAt stop0 km / h, 0 MPH
IGNITION ADVANCE
(IGNITION TIMING
ADVANCE FOR NO.1
CYLINDER)
At specified idle speed with no load after
warming up–1 – 18 BTDC
INTAKE AIR TEMP.At specified idle speed after warming up+35C (+63F)
–5C (–9F)
MAF (MASS AIR FLOW
RATE)
At specified idle speed with no load after
warming up1.0 – 3.0 gm / sec
RATE)At 2500 r / min with no load after warming up3.0 – 6.0 gm / sec
THROTTLE POS
(ABSOLUTEIgnition switch ON /Throttle valve fully closed7 – 18%
(ABSOLUTE
THROTTLE POSITION)
g
engine stoppedThrottle valve fully open70 – 90%
O2S B1 S1 (HEATED
OXYGEN SENSOR-1)At specified idle speed after warming up0.05 – 0.95 V
O2S B1 S2 (HEATED
OXYGEN SENSOR-2)When engine is running at 2000 r / min. for
3 min. or longer after warming up.0 – 0.95 V
O2S FT B1 S1At specified idle speed after warning up–20 – +20%
DIS. WITH MIL ON————